- Remove unused GetSuffix function

- Renamed FileReadable -> FileIsReadable
- Remove support for GROKS_DASH_O; deferr it to %opts% substitution
- Require a -o option except in case of linking where it defaults to a.out
- Fix problem processing *.o and *.bc files.
- Ignore optimization phase if -emit-raw-code
- Correct the assembly generation phase to support -emit-native-code
- Implement dependent library lookup

llvm-svn: 16020