Refactoring of timevar API

Refactoring of timevar API

gcc/ChangeLog:
	* main.c (main): Pass in NULL for toplev's external_timer.
	* timevar.c: Include coretypes.h.
	(class timer::named_items): New.
	(timer::named_items::named_items): New.
	(timer::named_items::~named_items): New.
	(timer::named_items::push): New.
	(timer::named_items::pop): New.
	(timer::named_items::print): New.
	(timer::timer): Initialize field "m_jit_client_items".
	(timer::~timer): New.
	(timer::push): Move bulk of implementation to...
	(timer::push_internal): ...here.  New function.
	(timer::pop): Move bulk of implementation to...
	(timer::pop_internal): ...here.  New function.
	(timer::push_client_item): New.
	(timer::pop_client_item): New.
	(timer::print_row): New function, taken from timer::print.
	(timer::print): Print "GCC items" header if we also have client
	items.  Move row-printing to timer::print_row.  Print any client
	items.
	(timer::get_topmost_item_name): New method.
	* timevar.def (TV_JIT_ACQUIRING_MUTEX): New.
	(TV_JIT_CLIENT_CODE): New.
	* timevar.h (timer::push_client_item): New declaration.
	(timer::pop_client_item): New declaration.
	(timer::get_topmost_item_name): New method.
	(timer::push_internal): New declaration.
	(timer::pop_internal): New declaration.
	(timer::print_row): New declaration.
	(timer::named_items): New declaration.
	(timer::m_jit_client_items): New field.
	(timer): Add friend class named_items.
	(auto_timevar::auto_timevar): Add timer param.
	(auto_timevar::~auto_timevar): Use field "m_timer".
	(auto_timevar::m_timer): New field.
	* toplev.c (initialize_rtl): Add g_timer as param when
	constructing auto_timevar instance.
	(toplev::toplev): Add "external_timer" param, and use it to
	initialize the "g_timer" global if non-NULL.
	(toplev::~toplev): If this created "g_timer", delete it.
	* toplev.h (toplev::toplev): Replace "use_TV_TOTAL" bool param
	with "external_timer" timer *.

gcc/jit/ChangeLog:
	* docs/topics/compatibility.rst (LIBGCCJIT_ABI_4): New.
	* docs/topics/contexts.rst (GCC_JIT_BOOL_OPTION_DUMP_SUMMARY):
	We no longer show a profile.
	* docs/topics/index.rst (Topic Reference): Add performance.rst.
	* docs/topics/performance.rst: New file.
	* docs/_build/texinfo/libgccjit.texi: Regenerate.
	* jit-playback.c (gcc::jit::playback::context::compile): Add timer
	param when constructing the "toplev" instance.
	(gcc::jit::playback::context::acquire_mutex): Add timer param when
	constructing auto_timevar instance.
	(gcc::jit::playback::context::make_fake_args): If we have a timer,
	add "-ftime-report".
	(gcc::jit::playback::context::invoke_driver): Add timer param when
	constructing auto_timevar instance.
	(gcc::jit::playback::context::dlopen_built_dso): Likewise.
	* jit-playback.h (gcc::jit::playback::context::get_timer): New accessor.
	* jit-recording.c: Include timevar.h.
	(gcc::jit::recording::context::context): Initialize field "m_timer".
	* jit-recording.h: Add forward declaration of class timer.
	(gcc::jit::recording::context::set_timer): New method.
	(gcc::jit::recording::context::get_timer): New method.
	(gcc::jit::recording::context::m_timer): New field.
	* libgccjit++.h (gccjit::timer): New class.
	(gccjit::auto_time): New class.
	(gccjit::context::set_timer): New method.
	(gccjit::context::get_timer): New.
	(gccjit::timer::timer): New.
	(gccjit::timer::push): New.
	(gccjit::timer::pop): New.
	(timer::print): New.
	(timer::get_inner_timer): New.
	(timer::release): New.
	(auto_time::auto_time): New.
	(auto_time::~auto_time): New.
	* libgccjit.c: Include timevar.h.
	(struct gcc_jit_timer): New.
	(gcc_jit_timer_new): New function.
	(gcc_jit_timer_release): New function.
	(gcc_jit_context_set_timer): New function.
	(gcc_jit_context_get_timer): New function.
	(gcc_jit_timer_push): New function.
	(gcc_jit_timer_pop): New function.
	(gcc_jit_timer_print): New function.
	* libgccjit.h (LIBGCCJIT_HAVE_TIMING_API): New macro.
	(gcc_jit_timer): New typedef.
	(gcc_jit_timer_new): New function.
	(gcc_jit_timer_release): New function.
	(gcc_jit_context_set_timer): New function.
	(gcc_jit_context_get_timer): New function.
	(gcc_jit_timer_push): New function.
	(gcc_jit_timer_pop): New function.
	(gcc_jit_timer_print): New function.
	* libgccjit.map (LIBGCCJIT_ABI_4): New.
	(gcc_jit_timer_new): New function.
	(gcc_jit_timer_release): New function.
	(gcc_jit_context_set_timer): New function.
	(gcc_jit_context_get_timer): New function.
	(gcc_jit_timer_push): New function.
	(gcc_jit_timer_pop): New function.
	(gcc_jit_timer_print): New function.

gcc/testsuite/ChangeLog:
	* jit.dg/test-benchmark.c (test_jit): Add param "timer" and use
	it to push/pop timing items.
	(main): For each optimization level, create a gcc_jit_timer, and
	time all of the iteration within that level cumulatively.
	* jit.dg/test-error-gcc_jit_timer_pop-mismatch.c: New test case.
	* jit.dg/test-error-gcc_jit_timer_pop-too-many.c: New test case.

From-SVN: r226530