fix syntax errors

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

@@ -9,12 +9,12 @@ test('testblockalloc', compose(c_src,
 test('bug1010', normal, compile_and_run, ['+RTS -c -RTS'])
 test('derefnull',
              # SIGSEGV on Linux
-     compose(exit_code(139),
+     composes([exit_code(139),
              # SIGBUS on OX X
-             exit_code_if_platform(138, 'i386-apple-darwin')),
-             exit_code_if_platform(138, 'powerpc-apple-darwin')),
+             exit_code_if_platform(138, 'i386-apple-darwin'),
+             exit_code_if_platform(138, 'powerpc-apple-darwin'),
              # 5 on Windows - XXX why is that?
-             exit_code_if_platform(5, 'i386-unknown-mingw32')),
+             exit_code_if_platform(5, 'i386-unknown-mingw32')]),
      compile_and_run, [''])
 test('divbyzero',
              # SIGFPE on Linux