Driver: whitespace

Fixup some whitespace/style issues.  NFC.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@225012 91177308-0d34-0410-b5e6-96231b3b80d8
Driver: unify compiler-rt component selection

Unify the component handling for compiler-rt.  The components are regularly
named, built up from:

  ${LIBRARY_PREFIX}clang_rt.${component}-${arch}[-${environment}]${LIBRARY_SUFFIX}

Unify the handling for all the various components, into a single path to link
against the various components in a number of places.  This reduces duplication
of the clang_rt library name construction logic.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@225013 91177308-0d34-0410-b5e6-96231b3b80d8