Setting -DGCC_INSTALL_PREFIX causes tests to fail

[Dmitri Gribenko]

Hi,

Setting -DGCC_INSTALL_PREFIX causes tests to fail.  Try:

cmake -DGCC_INSTALL_PREFIX=/usr ...

The following tests fail:

    Clang :: Driver/constructors.c
    Clang :: Driver/hexagon-toolchain-elf.c
    Clang :: Driver/hexagon-toolchain.c
    Clang :: Driver/linux-header-search.cpp
    Clang :: Driver/linux-ld.c
    Clang :: Driver/pic.c

The issue is that GCC_INSTALL_PREFIX overrides sysroot -- see
Generic_GCC::GCCInstallationDetector::GCCInstallationDetector around
getGCCToolchainDir() call.  I'm not sure how to fix this.

Dmitri

--
main(i,j){for(i=2;;i++){for(j=2;j<i;j++){if(!(i%j)){j=0;break;}}if
(j){printf("%d\n",i);}}} /*Dmitri Gribenko <gribozavr at gmail.com>*/