InstrProf: Remove MSVC-specific logic

Apparently, MSVC has stdint.h now?  Let's see if the buildbots complain.
I'm not convinced that the build system is even set up for MSVC to build
this file, but...

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@204515 91177308-0d34-0410-b5e6-96231b3b80d8
Avoid GCC's "cast from pointer to integer of different size" warning.

This is a bit of a stab in the dark as I'm not sure I've got these
source files compiling correctly locally. (and the warning only
reproduces on a 32bit build anyway)

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@204521 91177308-0d34-0410-b5e6-96231b3b80d8