Fix #10717, fix #13284 (#13307)

Author: genotrance

config/nim.cfg

@@ -85,15 +85,28 @@ path="$lib/pure"
 
 @if unix and mingw:
   # Cross compile for Windows from Linux/OSX using MinGW
-  os = windows
-
-  i386.windows.gcc.path = "/usr/bin"
   i386.windows.gcc.exe = "i686-w64-mingw32-gcc"
   i386.windows.gcc.linkerexe = "i686-w64-mingw32-gcc"
+  i386.windows.gcc.cpp.exe = "i686-w64-mingw32-g++"
+  i386.windows.gcc.cpp.linkerexe = "i686-w64-mingw32-g++"
 
-  amd64.windows.gcc.path = "/usr/bin"
   amd64.windows.gcc.exe = "x86_64-w64-mingw32-gcc"
   amd64.windows.gcc.linkerexe = "x86_64-w64-mingw32-gcc"
+  amd64.windows.gcc.cpp.exe = "x86_64-w64-mingw32-g++"
+  amd64.windows.gcc.cpp.linkerexe = "x86_64-w64-mingw32-g++"
+
+  @if macosx:
+    i386.windows.gcc.path = "/usr/local/bin"
+    amd64.windows.gcc.path = "/usr/local/bin"
+  @else:
+    i386.windows.gcc.path = "/usr/bin"
+    amd64.windows.gcc.path = "/usr/bin"
+  @end
+
+  os = windows
+
+  gcc.options.linker = ""
+  gcc.cpp.options.linker = ""
 @end
 
 @if unix: