getRawNumberOfSymbols() assumes that a symbol table exists, which isn't
always guaranteed, while getNumberOfSymbols() handles and tolerates objects
without a symbol table. When there is a symbol table, both methods return
the same value.
Also add a test to ensure we don't regress in this regard. The test
generates a basic COFF object with symbols and overrides the symbol table
pointer with zeros to craft the input required to verify llvm-objcopy works
as expected in this scenario.
libtool uses file names to name members of an static library.
Files, located in different directories and having matching name,
would have the same name inside an archive. This is not a problem
for ld, but may be a problem for ar. This patch renames files
from ObjCopy library to avoid names clashing.
See https://reviews.llvm.org/D88827#3335814
Differential Revision: https://reviews.llvm.org/D120345
