Add AMD64 to sys config so msvccompiler get_build_version works

Python/getcompiler.c

@@ -10,7 +10,22 @@
 #if defined(__clang__)
 #define COMPILER "[Clang " __clang_version__ "]"
 #elif defined(__GNUC__)
-#define COMPILER "[GCC " __VERSION__ "]"
+/* To not break compatibility with things that determine
+   CPU arch by calling get_build_version in msvccompiler.py
+   (such as NumPy) add "32 bit" or "64 bit (AMD64)" on Windows
+   and also use a space as a separator rather than a newline. */
+#if defined(_WIN32)
+#define COMP_SEP " "
+#if defined(__x86_64__)
+#define ARCH_SUFFIX " 64 bit (AMD64)"
+#else
+#define ARCH_SUFFIX " 32 bit"
+#endif
+#else
+#define COMP_SEP "\n"
+#define ARCH_SUFFIX ""
+#endif
+#define COMPILER COMP_SEP "[GCC " __VERSION__ ARCH_SUFFIX "]"
 // Generic fallbacks.
 #elif defined(__cplusplus)
 #define COMPILER "[C++]"