Use 64bit Windows compiler on 64bit Windows

Author: Earle F. Philhower, III

tools/get.py

@@ -97,7 +97,7 @@ def identify_platform():
     arduino_platform_names = {'Darwin'  : {32 : 'i386-apple-darwin',   64 : 'x86_64-apple-darwin'},
                               'Linux'   : {32 : 'i686-pc-linux-gnu',   64 : 'x86_64-pc-linux-gnu'},
                               'LinuxARM': {32 : 'arm-linux-gnueabihf', 64 : 'aarch64-linux-gnu'},
-                              'Windows' : {32 : 'i686-mingw32',        64 : 'i686-mingw32'}}
+                              'Windows' : {32 : 'i686-mingw32',        64 : 'x86_64-mingw32'}}
     bits = 32
     if sys.maxsize > 2**32:
         bits = 64