[Profile] Always build profile runtime library with -fPIC.

This change removes libclang_rt.profile-pic-<arch>.a version of
profile runtime. Instead, it's sufficient to always build
libclang_rt.profile-<arch>.a with -fPIC, as it can be linked into
both executables and shared objects.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@221952 91177308-0d34-0410-b5e6-96231b3b80d8