Demangler integer overflow fixes from Marcel Böhme.

Demangler integer overflow fixes from Marcel Böhme.

	PR c++/70498
	* cp-demangle.c: Parse numbers as integer instead of long to avoid
	overflow after sanity checks. Include <limits.h> if available.
	(INT_MAX): Define if necessary.
	(d_make_template_param): Takes integer argument instead of long.
	(d_make_function_param): Likewise.
	(d_append_num): Likewise.
	(d_identifier): Likewise.
	(d_number): Parse as and return integer.
	(d_compact_number): Handle overflow.
	(d_source_name): Change variable type to integer for parsed number.
	(d_java_resource): Likewise.
	(d_special_name): Likewise.
	(d_discriminator): Likewise.
	(d_unnamed_type): Likewise.
	* testsuite/demangle-expected: Add regression test cases.

From-SVN: r235767