Disable x87 control word for non-x86 targets

On msvc, x87 control word is only available on x86 target. Need to disable it for other targets to prevent compiling problems.

Author: gongminmin

Include/pyport.h

@@ -406,7 +406,7 @@ extern "C" {
 #endif
 
 /* get and set x87 control word for VisualStudio/x86 */
-#if defined(_MSC_VER) && !defined(_WIN64) /* x87 not supported in 64-bit */
+#if defined(_MSC_VER) && defined(_M_IX86) /* x87 only supported in x86 */
 #define HAVE_PY_SET_53BIT_PRECISION 1
 #define _Py_SET_53BIT_PRECISION_HEADER \
     unsigned int old_387controlword, new_387controlword, out_387controlword