[Support] Move ItaniumManglingCanonicalizer and SymbolRemappingReader from Support to ProfileData

As mentioned on https://discourse.llvm.org/t/issues-in-llvm-tblgen-high-parallelized-build/68037, ItaniumManglingCanonicalizer is often slow to build, resulting in a bottleneck for distributed builds while waiting for LLVMSupport to complete.

SymbolRemappingReader is the only current user of ItaniumManglingCanonicalizer, and this is only used by ProfileData and llvm-cxxmap - so I propose we move both files into the ProfileData library.

Differential Revision: https://reviews.llvm.org/D143318