[runtimes] When COMPILER_RT is enabled, consider SANITIZER prefixes

Currently we passthrough CMake variables based on project prefix,
i.e. LIBCXX_, LIBCXXABI_, LIBUNWIND_ and COMPILER_RT_. However, many
compiler-rt flags start with SANITIZER_ rather than COMPILER_RT, so
passthrough those as well.

Differential Revision: https://reviews.llvm.org/D75773