This is actually needed, otherwise libc won't be added at all. For
instance when building libclang.so all the libc symbols won't be
found, with ld warning about libc being an "implicit dependency".
Patch by Xan López!
llvm-svn: 247603
This patch refactors the code to use the GCC installation detector
(modified so that it works in Solaris), and uses
ToolChain::GetFilePath everywhere once it works.
Patch by Xan López <xan@igalia.com>!
llvm-svn: 246473