PR10867: Analogue of r169441 for when using external 'sh'. And actually run the test!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169446 91177308-0d34-0410-b5e6-96231b3b80d8

Author: zygoloid

test/tools/llvm-lit/lit.local.cfg

@@ -0,0 +1 @@
+config.suffixes = ['.c']

utils/lit/lit/TestRunner.py

@@ -357,7 +357,7 @@ def executeScript(test, litConfig, tmpBase, commands, cwd):
     if isWin32CMDEXE:
         f.write('\nif %ERRORLEVEL% NEQ 0 EXIT\n'.join(commands))
     else:
-        f.write(' &&\n'.join(commands))
+        f.write('{ ' + '; } &&\n{ '.join(commands) + '; }')
     f.write('\n')
     f.close()