Win32 broken with GHC 7.10 RC3
Using the 32bit Windows build of GHC 7.10 RC3 (ghc-7.10.0.20150316) I can't load the Win32 library. I get the problem:
```
C:\Neil>ghci
GHCi, version 7.10.0.20150316: http://www.haskell.org/ghc/ :? for help
Prelude> import System.Win32
Prelude System.Win32> wRITE_DAC
<interactive>: C:\ghc\ghc-7.10.0.20150316\lib\Win32_6dnIMpnCmqmCdDB983aKnr\HSWin
32-2.3.1.0-6dnIMpnCmqmCdDB983aKnr.o: unknown symbol `_SetWindowLongPtrW'
ghc.exe: unable to load package `Win32-2.3.1.0'
```
This seems very serious, and breaks all packages that indirectly depend on the Win32 module (which on Windows is most of them).
<details><summary>Trac metadata</summary>
| Trac field | Value |
| ---------------------- | ------------ |
| Version | 7.10.1-rc3 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture | |
</details>
<!-- {"blocked_by":[],"summary":"Win32 broken with GHC 7.10 RC3","status":"New","operating_system":"","component":"Compiler","related":[],"milestone":"","resolution":"Unresolved","owner":{"tag":"Unowned"},"version":"7.10.1-rc3","keywords":[],"differentials":[],"test_case":"","architecture":"","cc":[""],"type":"Bug","description":"Using the 32bit Windows build of GHC 7.10 RC3 (ghc-7.10.0.20150316) I can't load the Win32 library. I get the problem:\r\n\r\n{{{\r\nC:\\Neil>ghci\r\nGHCi, version 7.10.0.20150316: http://www.haskell.org/ghc/ :? for help\r\nPrelude> import System.Win32\r\nPrelude System.Win32> wRITE_DAC\r\n<interactive>: C:\\ghc\\ghc-7.10.0.20150316\\lib\\Win32_6dnIMpnCmqmCdDB983aKnr\\HSWin\r\n32-2.3.1.0-6dnIMpnCmqmCdDB983aKnr.o: unknown symbol `_SetWindowLongPtrW'\r\nghc.exe: unable to load package `Win32-2.3.1.0'\r\n}}}\r\n\r\nThis seems very serious, and breaks all packages that indirectly depend on the Win32 module (which on Windows is most of them).","type_of_failure":"OtherFailure","blocking":[]} -->
issue