systools: fix gcc version detecton on non-english locale
systools: fix gcc version detecton on non-english locale

Summary:
ghc runs 'gcc -v' to check if we run under vanilla gcc
or disaguised clang by checking for string

    "gcc version <something>"

But this check does not always work as gcc has that string
localized via gettext mechanism:

    (some gcc's locale strings)
    be.po-msgstr "версія gcc %s\n"
    da.po-msgstr "GCC version %s\n"
    de.po-msgstr "gcc-Version %s %s\n"
    el.po-msgstr "έκδοση gcc %s\n"
    ...

To ping gcc to English locale we now override environment
variable with 'LANGUAGE=en' value.

Fixes Issue #8825

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

Test Plan: validate

Reviewers: austin

Reviewed By: austin

Subscribers: simonmar, ezyang, carter

Differential Revision: https://phabricator.haskell.org/D185

GHC Trac Issues: #8825

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