Synchronize libiberty sources with FSF GCC mainline version.

Synchronize libiberty sources with FSF GCC mainline version.

include	* libiberty.h (MAX_ALLOCA_SIZE): New macro.

libiberty * make-relative-prefix.c (make_relative_prefix_1): Fall back to
	malloc if alloca argument is greater than MAX_ALLOCA_SIZE.

	* cp-demangle.c (cplus_demangle_operators): Add f[lrLR].
	(d_expression_1): Handle them.
	(d_maybe_print_fold_expression): New.
	(d_print_comp_inner): Use it.
	(d_index_template_argument): Handle negative index.

	* cp-demangle.c (cplus_demangle_operators): Add sP and sZ.
	(d_print_comp_inner): Handle them.
	(d_template_args_1): Split out from d_template_args.
	(d_args_length): New.

	PR c++/70926
	* cplus-dem.c: Handle large values and overflow when demangling
	length variables.
	(demangle_template_value_parm): Read only until end of mangled string.
	(do_hpacc_template_literal): Likewise.
	(do_type): Handle overflow when demangling array indices.

	* cp-demangle.c (cplus_demangle_print_callback): Avoid zero-length
	  VLAs.

	PR c++/70498
	* cp-demangle.c (d_expression_1): Formatting fix.

	* cplus-dem.c (enum type_kind_t): Add tk_rvalue_reference
	constant.
	(demangle_template_value_parm): Handle tk_rvalue_reference
	type kind.
	(do_type): Support 'O' type id (rvalue references).

	* testsuite/demangle-expected: Add tests.

	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.

	* configure: Remove SH5 support.

	PR c++/69687
	* cplus-dem.c: Include <limits.h> if available.
	(INT_MAX): Define if necessary.
	(remember_type, remember_Ktype, register_Btype, string_need):
	Abort if we detect cases where we the size of the allocation would
	overflow.

	PR c++/70492
	* cplus-dem.c (gnu_special): Handle case where consume_count returns
	-1.

	PR c++/67394
	PR c++/70481
	* cplus-dem.c (squangle_mop_up): Zero bsize/ksize after freeing
	btypevec/ktypevec.
	* testsuite/demangle-expected: Add coverage tests.