Fix cgrun067

Rename the auxiliary module to work on case-insensitive filesystems,
and add extra-cleans for it.

testsuite/tests/ghc-regress/codeGen/should_run/Cgrun067.hs → testsuite/tests/ghc-regress/codeGen/should_run/Cgrun067A.hs

 -- Bug doesn't show up on -O0
 {-# OPTIONS_GHC -O #-}
-module Cgrun067 (miscompiledFn) where
+module Cgrun067A (miscompiledFn) where
 
 import Foreign.C
 import Foreign

testsuite/tests/ghc-regress/codeGen/should_run/all.T

@@ -73,7 +73,8 @@ test('cgrun062', normal, compile_and_run, [''])
 test('cgrun063', normal, compile_and_run, [''])
 test('cgrun065', normal, compile_and_run, [''])
 test('cgrun066', normal, compile_and_run, [''])
-test('cgrun067', normal, compile_and_run, [''])
+test('cgrun067', extra_clean(['Cgrun067A.hi', 'Cgrun067A.o']),
+     compile_and_run, [''])
 
 test('1861', extra_run_opts('0'), compile_and_run, [''])
 

testsuite/tests/ghc-regress/codeGen/should_run/cgrun067.hs

@@ -5,7 +5,7 @@
 
 -- Miscompiled code must be in another module, otherwise problem doesn't
 -- show up.
-import Cgrun067 (miscompiledFn)
+import Cgrun067A (miscompiledFn)
 import Foreign.C.String
 
 main = withCString "foobar" $ \p -> print =<< miscompiledFn p