[Memprof] Reduce test binary sizes for memprof tests. (#97114)
PR 94264 had substantial increase in test binary size. This was due to
building LLVM and compiler-rt with GCC, implicitly causing the runtimes
to be built with full debuginfo. Rebuilding LLVM with
`-DCMAKE_CXX_COMPILER=/usr/bin/clang++` and regenerating .exe files with
script `update_memprof_inputs.sh` avoids this increase in test binary
size.