Windows ASan: Instrument _msize_base()

Summary:
A recent update to the VS toolchain in chromium [1] broke the windows
ASan bot because the new toolchain calls _msize_base() instead of
_msize() in a number of _aligned_* UCRT routines. Instrument
_msize_base() as well.

[1] https://crbug.com/914947

Reviewers: rnk, #sanitizers, vitalybuka

Reviewed By: rnk, #sanitizers, vitalybuka

Subscribers: vitalybuka, kubamracek, llvm-commits

Differential Revision: https://reviews.llvm.org/D55684

llvm-svn: 349115