[2.26 COMMITTED 2/3] Fix the C++ version of issignaling when __NO_LONG_DOUBLE_MATH is defined

[Gabriel F. T. Gomes]

When __NO_LONG_DOUBLE_MATH is defined, __issignalingl is not available,
thus issignaling with long double argument should call __issignaling,
instead.

Tested for powerpc64le.

	* math/math.h [defined __cplusplus] (issignaling): In the long
	double case, call __issignalingl only if __NO_LONG_DOUBLE_MATH
	is not defined.  Call __issignaling, otherwise.

(cherry picked from commit 3d7b66f66cb223e899a7ebc0f4c20f13e711c9e0)
---
 ChangeLog   |  6 ++++++
 math/math.h | 10 +++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 527026ba5d..04b56b555c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-24  Gabriel F. T. Gomes  <gftg@linux.vnet.ibm.com>
+
+	* math/math.h [defined __cplusplus] (issignaling): In the long
+	double case, call __issignalingl only if __NO_LONG_DOUBLE_MATH
+	is not defined.  Call __issignaling, otherwise.
+
 2017-08-22  Gabriel F. T. Gomes  <gftg@linux.vnet.ibm.com>
 
 	* math/math.h [defined __cplusplus] (issignaling): Provide a C++
diff --git a/math/math.h b/math/math.h
index add86af724..60dfa31592 100644
--- a/math/math.h
+++ b/math/math.h
@@ -486,7 +486,15 @@ enum
 extern "C++" {
 inline int issignaling (float __val) { return __issignalingf (__val); }
 inline int issignaling (double __val) { return __issignaling (__val); }
-inline int issignaling (long double __val) { return __issignalingl (__val); }
+inline int
+issignaling (long double __val)
+{
+#  ifdef __NO_LONG_DOUBLE_MATH
+  return __issignaling (__val);
+#  else
+  return __issignalingl (__val);
+#  endif
+}
 #  if __HAVE_DISTINCT_FLOAT128
 inline int issignaling (_Float128 __val) { return __issignalingf128 (__val); }
 #  endif
-- 
2.13.5