Fix math constant defines in C11 mode
mathematical constants undefined if __STRICT_ANSI__ and _POSIX_C_SOURCE
or _POSIX_SOURCE is defined.
Patch by Thomas Uhle, thomas.uhle of mailbox.tu-dresden.de
(cherry picked from commit ce1ad456e50da040a1274d9d7292933abf413865)
diff --git a/mingw-w64-headers/crt/math.h b/mingw-w64-headers/crt/math.h
index 069e734..ce42ed1 100644
--- a/mingw-w64-headers/crt/math.h
+++ b/mingw-w64-headers/crt/math.h
@@ -36,7 +36,7 @@
#endif
#endif
-#if !defined(__STRICT_ANSI__) || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE) || defined(_USE_MATH_DEFINES)
+#if !defined(__STRICT_ANSI__) || defined(_POSIX_C_SOURCE) || defined(_POSIX_SOURCE) || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE) || defined(_USE_MATH_DEFINES)
#define M_E 2.7182818284590452354
#define M_LOG2E 1.4426950408889634074
#define M_LOG10E 0.43429448190325182765
