Enable isinf/isnan checks for all targets

	PR libstdc++/48891
	* acinclude.m4 (GLIBCXX_CHECK_MATH11_PROTO): Enable isinf and isnan
	checks for all targets except *-*-solaris2.* and ensure we find the
	libc math.h header not our own.
	* configure: Regenerate.

From-SVN: r233214

1 files changed, 5 insertions, 4 deletions

diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index a919a3e..02bb312 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -18266,7 +18266,7 @@ fi
       { $as_echo "$as_me:${as_lineno-$LINENO}: result: $glibcxx_cv_math11_overload" >&5
 $as_echo "$glibcxx_cv_math11_overload" >&6; }
       ;;
-    *-*-*gnu* | *-*-aix* | *-*-hpux*)
+    *)
       # If <math.h> defines the obsolete isinf(double) and isnan(double)
       # functions (instead of or as well as the C99 generic macros) then we
       # can't define std::isinf(double) and std::isnan(double) in <cmath>
@@ -18279,12 +18279,13 @@ else
 
           cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-#include <math.h>
+#define _GLIBCXX_INCLUDE_NEXT_C_HEADERS
+             #include <math.h>
              #undef isinf
              namespace std {
                using ::isinf;
-               bool isinf(float);
-               bool isinf(long double);
+               constexpr bool isinf(float);
+               constexpr bool isinf(long double);
              }
              using std::isinf;
              bool b = isinf(0.0);