mingw-w64-crt: Make fpclassify consistent for x86 against other archs

Fixes https://sourceforge.net/p/mingw-w64/bugs/367/
Patch by Carl Kleffner cmkleffner gmail dot com
diff --git a/mingw-w64-crt/math/fpclassify.c b/mingw-w64-crt/math/fpclassify.c
index 91c8b54..f7303ec 100644
--- a/mingw-w64-crt/math/fpclassify.c
+++ b/mingw-w64-crt/math/fpclassify.c
@@ -17,7 +17,6 @@
 
 int __fpclassify (double _x)
 {
-#if defined(__x86_64__) || defined(_AMD64_) || defined(__arm__) || defined(_ARM_)
     __mingw_dbl_type_t hlp;
     unsigned int l, h;
 
@@ -32,13 +31,4 @@
     if (h == 0x7ff00000)
       return (l ? FP_NAN : FP_INFINITE);
     return FP_NORMAL;
-#elif defined(__i386__) || defined(_X86_)
-  unsigned short sw;
-  __asm__ __volatile__ (
-	"fxam; fstsw %%ax;"
-	: "=a" (sw)
-	: "t" (_x)
-	);
-  return sw & (FP_NAN | FP_NORMAL | FP_ZERO);
-#endif
 }