Fix travis ci build for windows using auxiliary batch script to escape from git bash to visual studio.

mps/.travis.yml

@@ -13,6 +13,13 @@ compiler:
   - clang
   - gcc
 matrix:
+  include:
+    - os: linux
+      script: ./configure --prefix=$PWD/prefix && make install && make test
+    - os: osx
+      script: ./configure --prefix=$PWD/prefix && make install && make test
+    - os: windows
+      script: MSYS2_ARG_CONV_EXCL='*' cmd /k 'code\w3i6mv.bat'
   exclude:
     - os: osx
       compiler: gcc
@@ -23,5 +30,3 @@ notifications:
 #before_install:
 #  - if test "$TRAVIS_OS_NAME" = "linux"; then sudo apt-get -qq update; fi
 #  - if test "$TRAVIS_OS_NAME" = "linux"; then sudo apt-get install -y gcc-4.7; fi
-script:
-  - ./configure --prefix=$PWD/prefix && make install && make test

mps/code/w3i6mv.bat

@@ -0,0 +1,10 @@
+@rem w3i6mv.bat -- set up and invoke build from raw CMD on Windows
+@rem This can be invoked from a plain CMD from the MPS workspace
+@rem like this::
+@rem   code\w3i6mv.bat
+@rem or from Git Bash in Travis CI build machines like this::
+@rem   MSYS2_ARG_CONV_EXCL='*' cmd /k 'code\w3i6mv.bat'
+@rem which is how it's invoked from .travis.yml
+call "C:\Program Files (x86)\Microsoft Visual Studio\2017\BuildTools\VC\Auxiliary\Build\vcvarsall.bat" x64
+cd code
+nmake /f w3i6mv.nmk