tests: Don't make a missing llvm-gcc dir a fatal error.

llvm-svn: 96938

test/lit.cfg

@@ -40,8 +40,6 @@ if llvm_obj_root is not None:
     config.environment['PATH'] = path
 
     llvmgcc_dir = getattr(config, 'llvmgcc_dir', None)
-    if not llvmgcc_dir:
-        lit.fatal('No llvm-gcc dir set!')
     if llvmgcc_dir:
         path = os.path.pathsep.join((os.path.join(llvmgcc_dir, 'bin'),
                                      config.environment['PATH']))