Fix implicit __isinf declarations in exp

[Joseph S. Myers]

My recent exp patch introduced warnings about implicit __isinf
declarations in exp because e_exp.c didn't include <math.h>.  I've
applied this patch to fix this.  Because <math.h> can't be included
after <math_private.h> (because of macro definitions of __nan*), it
was necessary to put an include in
sysdeps/x86_64/fpu/multiarch/e_exp.c as well.

Tested x86_64.

2014-03-24  Joseph Myers  <joseph@codesourcery.com>

	* sysdeps/ieee754/dbl-64/e_exp.c: Include <math.h>.
	* sysdeps/x86_64/fpu/multiarch/e_exp.c
	[HAVE_FMA4_SUPPORT || HAVE_AVX_SUPPORT]: Likewise.

diff --git a/sysdeps/ieee754/dbl-64/e_exp.c b/sysdeps/ieee754/dbl-64/e_exp.c
index cd060ce..0ab078f 100644
--- a/sysdeps/ieee754/dbl-64/e_exp.c
+++ b/sysdeps/ieee754/dbl-64/e_exp.c
@@ -32,6 +32,7 @@
 /*                                                                         */
 /***************************************************************************/
 
+#include <math.h>
 #include "endian.h"
 #include "uexp.h"
 #include "mydefs.h"
diff --git a/sysdeps/x86_64/fpu/multiarch/e_exp.c b/sysdeps/x86_64/fpu/multiarch/e_exp.c
index 3c65028..d244954 100644
--- a/sysdeps/x86_64/fpu/multiarch/e_exp.c
+++ b/sysdeps/x86_64/fpu/multiarch/e_exp.c
@@ -1,5 +1,6 @@
 #if defined HAVE_FMA4_SUPPORT || defined HAVE_AVX_SUPPORT
 # include <init-arch.h>
+# include <math.h>
 # include <math_private.h>
 
 extern double __ieee754_exp_sse2 (double);

-- 
Joseph S. Myers
joseph@codesourcery.com