Fix alpha, powerpc build failures.

Fix alpha, powerpc build failures.

2000-06-21  Benjamin Kosnik  <bkoz@soma.redhat.com>

	Fix alpha, powerpc build failures.
	* acinclude.m4 (GLIBCPP_CHECK_MATH_SUPPORT): Substantially
	re-write. Need to check for both proper declaration when using a
	c++ compiler, and "C" linkage when linking. Do both, and if both
	exist, then define the HAVE_* bits in config.h.
	(GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_n): New, uber-macros. Does all.
	(GLIBCPP_CHECK_LINKER_FEATURES): Actually link and run this
	program, doh.

From-SVN: r34643