tools/Makefile: Don't look into $(TARGET_OS), but $(HOST_OS), to inspect availability of loadable module!
tools/Makefile: Don't look into $(TARGET_OS), but $(HOST_OS), to inspect availability of loadable module!

The last commit made run.build.step.test_llvm_1 to fail.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@120283 91177308-0d34-0410-b5e6-96231b3b80d8

chubbymaggie/asap,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,dslab-epfl/asap,llvm-mirror/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,chubbymaggie/asap,chubbymaggie/asap,llvm-mirror/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,apple/swift-llvm,llvm-mirror/llvm,apple/swift-llvm,dslab-epfl/asap,llvm-mirror/llvm,llvm-mirror/llvm,dslab-epfl/asap,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,llvm-mirror/llvm,chubbymaggie/asap,chubbymaggie/asap,chubbymaggie/asap,dslab-epfl/asap,llvm-mirror/llvm,apple/swift-llvm