[PATCH] PR79017 workaround incomplete C99 math on darwin

[Jonathan Wakely <jwakely at redhat dot com>]

Older versions of OS X (at least Leopard) are missing some
declarations of C99 functions from <math.h>, which causes our
configure test to decide that all C99 functions are missing from
<math.h>. Rather then splitting up the check into dozens of smaller
checks for individual functions (which would be stage 1 material) this
just adds a special case for the six missing functions, so that darwin
checks for them separately and defaines a new macro to say they're
missing.

	PR libstdc++/79017
	* acinclude.m4 (GLIBCXX_CHECK_C99_TR1): Check for llrint and llround
	functions separately on darwin and if they're missing define
	_GLIBCXX_NO_C99_ROUNDING_FUNCS.
	* config.h.in: Regenerate.
	* configure: Regenerate.
	* include/c_global/cmath [_GLIBCXX_NO_C99_ROUNDING_FUNCS] (llrint)
	(llrintf, llrintl, llround, llroundf, llroundl): Do not define.

Tested x86_64-linux, committed to trunk.

Attachment: patch.txt
Description: Text document