[OMPT] Disable by default on Windows

This is broken per PR36561 and PR36574, so disable it for now until
somebody interested can take a look. OMPT can still be activated manually
by passing -DLIBOMP_OMPT_SUPPORT=ON during configuration.

Differential Revision: https://reviews.llvm.org/D50086

llvm-svn: 338721
GitOrigin-RevId: ef8f73728858598b479301c20586a13039d15927
2 files changed