panic when compiling SHA

[Kazu Yamamoto (=?iso-2022-jp?B?GyRCOzNLXE9CSScbKEI=?=)]

Hi,

When I tried to build the SHA library with GHC head on on 32bit Linux,
GHC head got panic. GHC 7.4.2 can build SHA on the same machine.

Configuring SHA-1.6.1...
Building SHA-1.6.1...
Failed to install SHA-1.6.1
Last 10 lines of the build log ( /home/kazu/work/rpf/.cabal-sandbox/logs/SHA-1.6.1.log ):
Preprocessing library SHA-1.6.1...
[1 of 1] Compiling Data.Digest.Pure.SHA ( Data/Digest/Pure/SHA.hs, dist/dist-sandbox-ef3aaa11/build/Data/Digest/Pure/SHA.o )
ghc: panic! (the 'impossible' happened)
  (GHC version 7.7.20131202 for i386-unknown-linux):
	regSpill: out of spill slots!
       regs to spill = 1129
       slots left    = 677

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

--Kazu