testsuite: disable gcc's warnings about casts of incompatible prototypes in UNREG
testsuite: disable gcc's warnings about casts of incompatible prototypes in UNREG

Haskell's 'foreign import' declaraion does not have a way
to extress exact C prototypes (it ignores 'const' modifiers, exact pointer
types, etc.) which leads to warnings when C backend generates calls to such
functions:

    /tmp/ghc32698_0/ghc32698_10.hc:52:5:
         warning: conflicting types for built-in function ‘strlen’ [enabled by default]
         EF_(strlen);
             ^

Patch disables builtin functions for UNREG build
to workaround test failures due to stderr mismatch.

Fixes the following test failures:
    TEST="safePkg01 T5423 T7574 T3736"

Signed-off-by: Sergei Trofimovich <110fdadc76b6bce16977f568bdb4723eaed6fb3f@gentoo.org>

gcampax/ghc,nathyong/microghc-ghc,olsner/ghc,acowley/ghc,vTurbine/ghc,nushio3/ghc,olsner/ghc,mcschroeder/ghc,nathyong/microghc-ghc,mcschroeder/ghc,snoyberg/ghc,da-x/ghc,da-x/ghc,ezyang/ghc,shlevy/ghc,gridaphobe/ghc,olsner/ghc,GaloisInc/halvm-ghc,elieux/ghc,ezyang/ghc,wxwxwwxxx/ghc,nushio3/ghc,GaloisInc/halvm-ghc,acowley/ghc,mfine/ghc,AlexanderPankiv/ghc,elieux/ghc,forked-upstream-packages-for-ghcjs/ghc,bitemyapp/ghc,sgillespie/ghc,GaloisInc/halvm-ghc,nkaretnikov/ghc,da-x/ghc,sgillespie/ghc,mfine/ghc,snoyberg/ghc,spacekitteh/smcghc,green-haskell/ghc,snoyberg/ghc,bitemyapp/ghc,gridaphobe/ghc,oldmanmike/ghc,ml9951/ghc,olsner/ghc,mfine/ghc,AlexanderPankiv/ghc,gridaphobe/ghc,wxwxwwxxx/ghc,christiaanb/ghc,forked-upstream-packages-for-ghcjs/ghc,christiaanb/ghc,nathyong/microghc-ghc,wxwxwwxxx/ghc,AlexanderPankiv/ghc,gcampax/ghc,ghc-android/ghc,vikraman/ghc,acowley/ghc,GaloisInc/halvm-ghc,ezyang/ghc,GaloisInc/halvm-ghc,urbanslug/ghc,gcampax/ghc,nushio3/ghc,jstolarek/ghc,fmthoma/ghc,shlevy/ghc,nushio3/ghc,tjakway/ghcjvm,green-haskell/ghc,anton-dessiatov/ghc,nushio3/ghc,urbanslug/ghc,nkaretnikov/ghc,jstolarek/ghc,siddhanathan/ghc,fmthoma/ghc,vTurbine/ghc,urbanslug/ghc,sgillespie/ghc,shlevy/ghc,ezyang/ghc,mcschroeder/ghc,nkaretnikov/ghc,ml9951/ghc,snoyberg/ghc,ghc-android/ghc,GaloisInc/halvm-ghc,sgillespie/ghc,tjakway/ghcjvm,vikraman/ghc,oldmanmike/ghc,bitemyapp/ghc,tjakway/ghcjvm,oldmanmike/ghc,nkaretnikov/ghc,TomMD/ghc,anton-dessiatov/ghc,jstolarek/ghc,elieux/ghc,oldmanmike/ghc,urbanslug/ghc,acowley/ghc,fmthoma/ghc,mettekou/ghc,vikraman/ghc,sdiehl/ghc,ezyang/ghc,oldmanmike/ghc,gcampax/ghc,nushio3/ghc,siddhanathan/ghc,fmthoma/ghc,spacekitteh/smcghc,snoyberg/ghc,nathyong/microghc-ghc,vTurbine/ghc,sdiehl/ghc,siddhanathan/ghc,AlexanderPankiv/ghc,nathyong/microghc-ghc,wxwxwwxxx/ghc,mcschroeder/ghc,vikraman/ghc,sgillespie/ghc,mfine/ghc,snoyberg/ghc,vTurbine/ghc,TomMD/ghc,ezyang/ghc,AlexanderPankiv/ghc,fmthoma/ghc,nathyong/microghc-ghc,mettekou/ghc,acowley/ghc,olsner/ghc,urbanslug/ghc,ml9951/ghc,mettekou/ghc,ghc-android/ghc,gcampax/ghc,nkaretnikov/ghc,forked-upstream-packages-for-ghcjs/ghc,tjakway/ghcjvm,jstolarek/ghc,snoyberg/ghc,ghc-android/ghc,christiaanb/ghc,sgillespie/ghc,mettekou/ghc,green-haskell/ghc,mfine/ghc,forked-upstream-packages-for-ghcjs/ghc,TomMD/ghc,acowley/ghc,gridaphobe/ghc,sdiehl/ghc,bitemyapp/ghc,sdiehl/ghc,da-x/ghc,elieux/ghc,shlevy/ghc,GaloisInc/halvm-ghc,christiaanb/ghc,jstolarek/ghc,TomMD/ghc,gridaphobe/ghc,anton-dessiatov/ghc,oldmanmike/ghc,TomMD/ghc,mettekou/ghc,ml9951/ghc,elieux/ghc,forked-upstream-packages-for-ghcjs/ghc,anton-dessiatov/ghc,elieux/ghc,nushio3/ghc,ghc-android/ghc,shlevy/ghc,tjakway/ghcjvm,shlevy/ghc,nkaretnikov/ghc,anton-dessiatov/ghc,spacekitteh/smcghc,green-haskell/ghc,da-x/ghc,urbanslug/ghc,forked-upstream-packages-for-ghcjs/ghc,TomMD/ghc,gcampax/ghc,ezyang/ghc,mfine/ghc,spacekitteh/smcghc,mcschroeder/ghc,wxwxwwxxx/ghc,bitemyapp/ghc,sdiehl/ghc,nathyong/microghc-ghc,acowley/ghc,tjakway/ghcjvm,nkaretnikov/ghc,green-haskell/ghc,olsner/ghc,gridaphobe/ghc,vTurbine/ghc,urbanslug/ghc,sdiehl/ghc,gridaphobe/ghc,da-x/ghc,christiaanb/ghc,forked-upstream-packages-for-ghcjs/ghc,vikraman/ghc,siddhanathan/ghc,sdiehl/ghc,vTurbine/ghc,AlexanderPankiv/ghc,ml9951/ghc,fmthoma/ghc,sgillespie/ghc,gcampax/ghc,fmthoma/ghc,spacekitteh/smcghc,oldmanmike/ghc,shlevy/ghc,olsner/ghc,anton-dessiatov/ghc,mettekou/ghc,ml9951/ghc,anton-dessiatov/ghc,TomMD/ghc,siddhanathan/ghc,da-x/ghc,wxwxwwxxx/ghc,tjakway/ghcjvm,mcschroeder/ghc,ghc-android/ghc,christiaanb/ghc,christiaanb/ghc,mettekou/ghc,wxwxwwxxx/ghc,ml9951/ghc,vikraman/ghc,vTurbine/ghc,siddhanathan/ghc,ml9951/ghc,mcschroeder/ghc,elieux/ghc,mfine/ghc,vikraman/ghc,siddhanathan/ghc,AlexanderPankiv/ghc,ghc-android/ghc