* tree.h (id_equal): New.

	* dwarf2out.c, hsa-gen.c, ipa-devirt.c, omp-expand.c,
	omp-simd-clone.c, read-rtl-function.c, tree-chkp.c, tree.c: Use it
	instead of strcmp of IDENTIFIER_POINTER.
c-family/
	* c-ada-spec.c, c-pragma.c: Use it.
cp/
	* cp-tree.h, decl2.c, mangle.c, parser.c, pt.c, semantics.c: Use it.

From-SVN: r249103