Add support for detecting mismatched allocation/deallocation calls.

Add support for detecting mismatched allocation/deallocation calls.

PR c++/90629 - Support for -Wmismatched-new-delete
PR middle-end/94527 - Add an __attribute__ that marks a function as freeing an object

gcc/ChangeLog:

	PR c++/90629
	PR middle-end/94527
	* builtins.c (access_ref::access_ref): Initialize new member.
	(compute_objsize): Use access_ref::deref.  Handle simple pointer
	assignment.
	(expand_builtin): Remove handling of the free built-in.
	(call_dealloc_argno): Same.
	(find_assignment_location): New function.
	(fndecl_alloc_p): Same.
	(gimple_call_alloc_p): Same.
	(call_dealloc_p): Same.
	(matching_alloc_calls_p): Same.
	(warn_dealloc_offset): Same.
	(maybe_emit_free_warning): Same.
	* builtins.h (struct access_ref): Declare new member.
	(maybe_emit_free_warning): Make extern.  Make use of access_ref.
	Handle -Wmismatched-new-delete.
	* calls.c (initialize_argument_information): Call
	maybe_emit_free_warning.
	* doc/extend.texi (attribute malloc): Update.
	* doc/invoke.texi (-Wfree-nonheap-object): Expand documentation.
	(-Wmismatched-new-delete): Document new option.
	(-Wmismatched-dealloc): Document new option.

gcc/c-family/ChangeLog:

	PR c++/90629
	PR middle-end/94527
	* c-attribs.c (handle_dealloc_attribute): New function.
	(handle_malloc_attribute): Handle argument forms of attribute.
	* c.opt (-Wmismatched-dealloc): New option.
	(-Wmismatched-new-delete): New option.

gcc/testsuite/ChangeLog:

	PR c++/90629
	PR middle-end/94527
	* g++.dg/asan/asan_test.cc: Fix a bug.
	* g++.dg/warn/delete-array-1.C: Add expected warning.
	* g++.old-deja/g++.other/delete2.C: Add expected warning.
	* g++.dg/warn/Wfree-nonheap-object-2.C: New test.
	* g++.dg/warn/Wfree-nonheap-object.C: New test.
	* g++.dg/warn/Wmismatched-new-delete.C: New test.
	* g++.dg/warn/Wmismatched-dealloc-2.C: New test.
	* g++.dg/warn/Wmismatched-dealloc.C: New test.
	* gcc.dg/Wmismatched-dealloc.c: New test.
	* gcc.dg/analyzer/malloc-1.c: Prune out expected warning.
	* gcc.dg/attr-malloc.c: New test.
	* gcc.dg/free-1.c: Adjust text of expected warning.
	* gcc.dg/free-2.c: Same.
	* gcc.dg/torture/pr71816.c: Prune out expected warning.
	* gcc.dg/tree-ssa/pr19831-2.c: Add an expected warning.
	* gcc.dg/Wfree-nonheap-object-2.c: New test.
	* gcc.dg/Wfree-nonheap-object-3.c: New test.
	* gcc.dg/Wfree-nonheap-object.c: New test.

libstdc++-v3/ChangeLog:

	* testsuite/ext/vstring/modifiers/clear/56166.cc: Suppress a false
	positive warning.