Remove support for %G and %K.

Remove support for %G and %K.

gcc/c-family/ChangeLog:

	* c-format.c (gcc_tdiag_char_table): Remove support for %G and %K.
	 (gcc_cdiag_char_table): Same.
	 (gcc_cxxdiag_char_table): Same.

gcc/c/ChangeLog:

	* c-objc-common.c (c_tree_printer): Remove support for %G and %K.

gcc/cp/ChangeLog:

	* error.c (cp_printer):  Remove support for %G and %K.

gcc/ChangeLog:

	* gimple-pretty-print.c (percent_G_format): Remove.
	* tree-diagnostic.c (default_tree_printer): Remove calls.
	* tree-pretty-print.c (percent_K_format): Remove.
	* tree-pretty-print.h (percent_K_format): Remove.

gcc/testsuite/ChangeLog:

	* gcc.dg/format/gcc_diag-10.c: Update expected warnings.
	* gcc.dg/plugin/diagnostic_plugin_test_inlining.c: Remove %G.