Add another layout test

testsuite/tests/ghc-regress/layout/Makefile

@@ -2,7 +2,7 @@ TOP=../../..
 include $(TOP)/mk/boilerplate.mk
 include $(TOP)/mk/test.mk
 
-layout001 layout002 layout003 layout004: %:
+layout001 layout002 layout003 layout004 layout005: %:
 	$(RM) $*.hi $*.o
 	echo Running with -XNoAlternativeLayoutRule
 	-"$(TEST_HC)" -XNoAlternativeLayoutRule -c $*.hs 2>&1

testsuite/tests/ghc-regress/layout/all.T

@@ -23,3 +23,9 @@ test('layout004',
      run_command,
      ['$MAKE -s --no-print-directory layout004'])
 
+test('layout005',
+     [extra_clean(['layout005.hi', 'layout005.o']),
+      only_compiler_types(['ghc'])],
+     run_command,
+     ['$MAKE -s --no-print-directory layout005'])
+

testsuite/tests/ghc-regress/layout/layout005.hs

+
+module M where
+
+-- GHC's Lexer.x had a piece of code like this
+
+f = if True then do
+        case () of
+            () -> ()
+            else ()
+

testsuite/tests/ghc-regress/layout/layout005.stdout

+Running with -XNoAlternativeLayoutRule
+Running with -XAlternativeLayoutRule
+
+layout005.hs:9:13: parse error on input `else'