sarif output: escape braces in messages [PR118675]

sarif output: escape braces in messages [PR118675]

gcc/ChangeLog:
	PR other/118675
	* diagnostic-format-sarif.cc: Define INCLUDE_STRING.
	(escape_braces): New.
	(set_string_property_escaping_braces): New.
	(sarif_builder::make_message_object): Escape braces in the "text"
	property.
	(sarif_builder::make_message_object_for_diagram): Likewise, and
	for the "markdown" property.
	(sarif_builder::make_multiformat_message_string): Likewise for the
	"text" property.
	(xelftest::test_message_with_braces): New.
	(selftest::diagnostic_format_sarif_cc_tests): Call it.

gcc/testsuite/ChangeLog:
	PR other/118675
	* gcc.dg/sarif-output/bad-binary-op.py: Update expected output for
	escaping of braces in message text.
	* gcc.dg/sarif-output/missing-semicolon.py: Likewise.
	* gcc.dg/sarif-output/multiple-outputs.py: Likewise.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>