* toplev.h (floor_log2): If GCC_VERSION >= 3004, declare as static
	inline, not extern inline.
	(exact_log2): Likewise.
	* toplev.c (floor_log2): Only define if GCC_VERSION < 3004. Don't
	test CLZ_HWI.
	(exact_log2): Likewise, but don't test CTZ_HWI.

From-SVN: r148540