THRIFT-4081: appveyor retooling - added mingw64 build as a second job to the CI build process

This closes #1205
diff --git a/build/appveyor/MING-appveyor-build.bat b/build/appveyor/MING-appveyor-build.bat
new file mode 100644
index 0000000..838e428
--- /dev/null
+++ b/build/appveyor/MING-appveyor-build.bat
@@ -0,0 +1,36 @@
+::
+:: Licensed under the Apache License, Version 2.0 (the "License");
+:: you may not use this file except in compliance with the License.
+:: You may obtain a copy of the License at
+::
+::     http://www.apache.org/licenses/LICENSE-2.0
+::
+:: Unless required by applicable law or agreed to in writing, software
+:: distributed under the License is distributed on an "AS IS" BASIS,
+:: WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+:: See the License for the specific language governing permissions and
+:: limitations under the License.
+::
+
+@ECHO OFF
+SETLOCAL EnableDelayedExpansion
+
+CD build\appveyor                           || EXIT /B
+CALL cl_banner_build.bat                    || EXIT /B
+CALL cl_setenv.bat                          || EXIT /B
+
+SET CMAKEARGS=^
+  -G'%GENERATOR%' ^
+  -DCMAKE_BUILD_TYPE=%CONFIGURATION% ^
+  -DCMAKE_INSTALL_PREFIX=%INSTDIR_MSYS% ^
+  -DCMAKE_MAKE_PROGRAM=/mingw64/bin/mingw32-make ^
+  -DCMAKE_C_COMPILER=x86_64-w64-mingw32-gcc.exe ^
+  -DCMAKE_CXX_COMPILER=x86_64-w64-mingw32-g++.exe ^
+  -DWITH_LIBEVENT=OFF ^
+  -DWITH_PYTHON=OFF ^
+  -DWITH_SHARED_LIB=OFF ^
+  -DWITH_STATIC_LIB=ON
+
+@ECHO ON
+%BASH% -lc "mkdir -p %BUILDDIR_MSYS% && cd %BUILDDIR_MSYS% && cmake.exe %SRCDIR_MSYS% %CMAKEARGS% && cmake --build . --config %CONFIGURATION% --target install" || EXIT /B
+@ECHO OFF