forkProcess now works with +RTS -N; update docs and tests

System/Posix/Process/Common.hsc

@@ -282,10 +282,6 @@ in case of an error, an exception is thrown.
 threads are not copied into the child process, it's easy to go wrong:
 e.g. by accessing some shared resource that was held by another thread
 in the parent.
-
-GHC note: 'forkProcess' is not currently supported when using multiple
-processors (@+RTS -N@), although it is supported with @-threaded@ as
-long as only one processor is being used.
 -}
 
 forkProcess :: IO () -> IO ProcessID

tests/all.T

@@ -8,7 +8,6 @@ test('signals002',  compose(only_compiler_types(['ghc']), conf),
 	compile_and_run, ['-package unix'])
 test('fileexist01', conf, compile_and_run, ['-package unix'])
 test('forkprocess01', [ only_compiler_types(['ghc']),
-                        expect_fail_for(['threaded2']),
                         extra_ways(['threaded1_ls']), # test #4512
                         conf ],
         compile_and_run, ['-package unix'])
@@ -53,8 +52,7 @@ test('fileStatusByteString',
      ['-package unix'])
 
 
-test('1185', [ expect_fail_for(['threaded2']) ], 
-             compile_and_run, ['-package unix'])
+test('1185', normal, compile_and_run, ['-package unix'])
 
 # This test fails for me on x86/Linux with a "does not exist" error.
 # Running with strace shows it is trying to talk to winbindd (part of