[MetaRenamer] Add command line options to disable renaming name with specified prefixes

This patch adds 4 options for specifying functions, aliases, globals and
structs name prefixes hat don't need to be renamed by MetaRenamer pass.
This is useful if one has some downstream logic that depends directly
on an entity name. MetaRenamer can break this logic, but with the patch
you can tell it not to rename certain names.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D115323