Argh!  Wait!  We've gone through weeks (possibly months) of pain trying to resolve the _USE_32BIT_TIME_T issue.  Anything involving that define affects more than just MSVC builds, and more than just building the Tcl core.  Please consider any change _very_ carefully.  Jan Nijtmans and I (to a lesser extent) can provide more background.

Better solution found. Including assert.h after tclInt.h in tclParse.h also solves the problem without the need for USE_32BIT_TIME_T.