Building Tcl with msys+vc++

Install msys from http://sourceforge.net/projects/mingwbuilds/files/external-binary-packages/
Note this is only msys, not msys+mingw since we are not using gcc
Uncompress into (e.g.) c:\msys
Use command shell, not msys sh. The latter will also work if you work around the confusion between the  VC++ link and the Gnu link executables (of course commands below will need to use shell syntax)
Use forward / in paths to configure
mkdir ..wherever..\builds (make sure no spaces in path)
mkdir …builds\tcl
mkdir …builds\tk
cd …builds\tcl
call setenv from wherever to set up paths and env for Visual C++
set CC=cl (to make configure use the MS compiler)
set LIBS=bufferoverflowU.lib (optional) needed for some compiler versions

If doing 64-bit builds
path-to-msys\bin\sh path-to-tcl/win/configure --prefix=TCL_INSTALL_DIR --enable-threads --enable-64bit
For 32-bit builds, leave off the --enable-64bit
Then,
make
make install