Make CC defaults to gcc.  The cxx_compiler and cxx_linker functions rely on substituting "g++" for "gcc".
Make CC defaults to gcc.  The cxx_compiler and cxx_linker functions rely on substituting "g++"
for "gcc".


git-svn-id: b33bab8abb5b18c12ee100cd7761ab452d00b2b0@123461 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb