Update libiberty sources with changes in the gcc mainline.

Update libiberty sources with changes in the gcc mainline.

+2020-01-01  Jakub Jelinek  <jakub@redhat.com>
+
+	Update copyright years.
+
+2019-12-06  Tim Ruehsen  <tim.ruehsen@gmx.de>
+
+	* make-relative-prefix.c (split_directories):
+	Return early on empty 'name'
+
+2019-11-16  Tim Ruehsen  <tim.ruehsen@gmx.de>
+
+	* cp-demangle.c (d_print_init): Remove const from 4th param.
+	(cplus_demangle_fill_name): Initialize d->d_counting.
+	(cplus_demangle_fill_extended_operator): Likewise.
+	(cplus_demangle_fill_ctor): Likewise.
+	(cplus_demangle_fill_dtor): Likewise.
+	(d_make_empty): Likewise.
+	(d_count_templates_scopes): Remobe const from 3rd param,
+	Return on dc->d_counting > 1,
+	Increment dc->d_counting.
+        * cp-demint.c (cplus_demangle_fill_component): Initialize d->d_counting.
+	(cplus_demangle_fill_builtin_type): Likewise.
+	(cplus_demangle_fill_operator): Likewise.
+
+2019-11-16  Eduard-Mihai Burtescu  <eddyb@lyken.rs>
+
+	* cplus-dem.c (cplus_demangle): Use rust_demangle directly.
+	(rust_demangle): Remove.
+	* rust-demangle.c (is_prefixed_hash): Rename to is_legacy_prefixed_hash.
+	(parse_lower_hex_nibble): Rename to decode_lower_hex_nibble.
+	(parse_legacy_escape): Rename to decode_legacy_escape.
+	(rust_is_mangled): Remove.
+	(struct rust_demangler): Add.
+	(peek): Add.
+	(next): Add.
+	(struct rust_mangled_ident): Add.
+	(parse_ident): Add.
+	(rust_demangle_sym): Remove.
+	(print_str): Add.
+	(PRINT): Add.
+	(print_ident): Add.
+	(rust_demangle_callback): Add.
+	(struct str_buf): Add.
+	(str_buf_reserve): Add.
+	(str_buf_append): Add.
+	(str_buf_demangle_callback): Add.
+	(rust_demangle): Add.
+	* rust-demangle.h: Remove.
+
+2019-11-15  Miguel Saldivar  <saldivarcher@gmail.com>
+
+	* testsuite/demangle-expected: Fix test.
+
+2019-11-04  Kamlesh Kumar  <kamleshbhalui@gmail.com>
+
+	* cp-demangle.c (d_expr_primary): Handle
+	nullptr demangling.
+	* testsuite/demangle-expected: Added test.
+
+2019-10-29 Paul Pluzhnikov  <ppluzhnikov@google.com>
+
+	* cp-demangle.c (d_number): Avoid signed int overflow.
+
+2019-10-28  Miguel Saldivar  <saldivarcher@gmail.com>
+
+	* cp-demangle.c (d_print_mod): Add a space before printing `complex`
+	and `imaginary`, as opposed to after.
+	* testsuite/demangle-expected: Adjust test.
+
+2019-10-03  Eduard-Mihai Burtescu  <eddyb@lyken.rs>
+
+	* rust-demangle.c (looks_like_rust): Remove.
+	(rust_is_mangled): Don't check escapes.
+	(is_prefixed_hash): Allow 0-9a-f permutations.
+	(rust_demangle_sym): Don't bail on unknown escapes.
+	* testsuite/rust-demangle-expected: Update 'main::$99$' test.
+
+2019-09-03  Eduard-Mihai Burtescu  <eddyb@lyken.rs>
+
+	* rust-demangle.c (unescape): Remove.
+	(parse_lower_hex_nibble): New function.
+	(parse_legacy_escape): New function.
+	(is_prefixed_hash): Use parse_lower_hex_nibble.
+	(looks_like_rust): Use parse_legacy_escape.
+	(rust_demangle_sym): Use parse_legacy_escape.
+	* testsuite/rust-demangle-expected: Add 'llv$u6d$' test.
+
+2019-08-27  Martin Liska  <mliska@suse.cz>
+
+	PR lto/91478
+	* simple-object-elf.c (simple_object_elf_copy_lto_debug_sections):
+	First find a WEAK HIDDEN symbol in symbol table that will be
+	preserved.  Later, use the symbol name for all removed symbols.
+
+2019-08-12  Martin Liska  <mliska@suse.cz>
+
+	* Makefile.in: Add filedescriptor.c.
+	* filedescriptor.c: New file.
+	* lrealpath.c (is_valid_fd): Remove.

diff --git a/libiberty/Makefile.in b/libiberty/Makefile.in
index 0be45b4ae8..fe738d0db4 100644
--- a/libiberty/Makefile.in
+++ b/libiberty/Makefile.in
@@ -1,7 +1,7 @@
 # Makefile for the libiberty library.
 # Originally written by K. Richard Pixley <rich@cygnus.com>.
 #
-# Copyright (C) 1990-2019 Free Software Foundation, Inc.
+# Copyright (C) 1990-2020 Free Software Foundation, Inc.
 #
 # This file is part of the libiberty library.
 # Libiberty is free software; you can redistribute it and/or
@@ -127,7 +127,7 @@ CFILES = alloca.c argv.c asprintf.c atexit.c				\
 	calloc.c choose-temp.c clock.c concat.c cp-demangle.c		\
 	 cp-demint.c cplus-dem.c crc32.c				\
 	d-demangle.c dwarfnames.c dyn-string.c				\
-	fdmatch.c ffs.c fibheap.c filename_cmp.c floatformat.c		\
+	fdmatch.c ffs.c fibheap.c filedescriptor.c filename_cmp.c floatformat.c		\
 	fnmatch.c fopen_unlocked.c					\
 	getcwd.c getopt.c getopt1.c getpagesize.c getpwd.c getruntime.c	\
          gettimeofday.c                                                 \
@@ -171,6 +171,7 @@ REQUIRED_OFILES =							\
 	./cp-demint.$(objext) ./crc32.$(objext) ./d-demangle.$(objext)	\
 	./dwarfnames.$(objext) ./dyn-string.$(objext)			\
 	./fdmatch.$(objext) ./fibheap.$(objext)				\
+	./filedescriptor.$(objext)	\
 	./filename_cmp.$(objext) ./floatformat.$(objext)		\
 	./fnmatch.$(objext) ./fopen_unlocked.$(objext)			\
 	./getopt.$(objext) ./getopt1.$(objext) ./getpwd.$(objext)	\
@@ -756,6 +757,17 @@ $(CONFIGURED_OFILES): stamp-picdir stamp-noasandir
 	else true; fi
 	$(COMPILE.c) $(srcdir)/fibheap.c $(OUTPUT_OPTION)

+./filedescriptor.$(objext): $(srcdir)/filedescriptor.c config.h $(INCDIR)/ansidecl.h \
+	$(INCDIR)/libiberty.h
+	if [ x"$(PICFLAG)" != x ]; then \
+	  $(COMPILE.c) $(PICFLAG) $(srcdir)/filedescriptor.c -o pic/$@; \
+	else true; fi
+	if [ x"$(NOASANFLAG)" != x ]; then \
+	  $(COMPILE.c) $(PICFLAG) $(NOASANFLAG) $(srcdir)/filedescriptor.c -o noasan/$@; \
+	else true; fi
+	$(COMPILE.c) $(srcdir)/filedescriptor.c $(OUTPUT_OPTION)
+
+
 ./filename_cmp.$(objext): $(srcdir)/filename_cmp.c config.h $(INCDIR)/ansidecl.h \
 	$(INCDIR)/filenames.h $(INCDIR)/hashtab.h \
 	$(INCDIR)/safe-ctype.h
diff --git a/libiberty/_doprnt.c b/libiberty/_doprnt.c
index d44dc415ed..a739f4304f 100644
--- a/libiberty/_doprnt.c
+++ b/libiberty/_doprnt.c
@@ -1,5 +1,5 @@
 /* Provide a version of _doprnt in terms of fprintf.
-   Copyright (C) 1998-2019 Free Software Foundation, Inc.
+   Copyright (C) 1998-2020 Free Software Foundation, Inc.
    Contributed by Kaveh Ghazi  (ghazi@caip.rutgers.edu)  3/29/98

 This program is free software; you can redistribute it and/or modify it
diff --git a/libiberty/argv.c b/libiberty/argv.c
index 6444896f99..8c9794db6a 100644
--- a/libiberty/argv.c
+++ b/libiberty/argv.c
@@ -1,5 +1,5 @@
 /* Create and destroy argument vectors (argv's)
-   Copyright (C) 1992-2019 Free Software Foundation, Inc.
+   Copyright (C) 1992-2020 Free Software Foundation, Inc.
    Written by Fred Fish @ Cygnus Support

 This file is part of the libiberty library.
diff --git a/libiberty/asprintf.c b/libiberty/asprintf.c
index 5718682f69..6e38e2234d 100644
--- a/libiberty/asprintf.c
+++ b/libiberty/asprintf.c
@@ -1,6 +1,6 @@
 /* Like sprintf but provides a pointer to malloc'd storage, which must
    be freed by the caller.
-   Copyright (C) 1997-2019 Free Software Foundation, Inc.
+   Copyright (C) 1997-2020 Free Software Foundation, Inc.
    Contributed by Cygnus Solutions.

 This file is part of the libiberty library.
diff --git a/libiberty/choose-temp.c b/libiberty/choose-temp.c
index 72c1b710bd..49a2faaa51 100644
--- a/libiberty/choose-temp.c
+++ b/libiberty/choose-temp.c
@@ -1,5 +1,5 @@
 /* Utility to pick a temporary filename prefix.
-   Copyright (C) 1996-2019 Free Software Foundation, Inc.
+   Copyright (C) 1996-2020 Free Software Foundation, Inc.

 This file is part of the libiberty library.
 Libiberty is free software; you can redistribute it and/or
diff --git a/libiberty/clock.c b/libiberty/clock.c
index a3730714bd..0de74657d0 100644
--- a/libiberty/clock.c
+++ b/libiberty/clock.c
@@ -1,5 +1,5 @@
 /* ANSI-compatible clock function.
-   Copyright (C) 1994-2019 Free Software Foundation, Inc.
+   Copyright (C) 1994-2020 Free Software Foundation, Inc.

 This file is part of the libiberty library.  This library is free
 software; you can redistribute it and/or modify it under the
diff --git