clang-3.7 3.7-r241984: build failed fatal error: 'mach/x86_64/task.h' file not found when xcode-4.x on mountain lion

[h.rayflood@…]

Thank you for landing my patch #47729

I tried to build r241984, and I got following error on mountain lion using xcode-4.x.

:info:build   COMPILE:   clang_darwin/asan_iossim_dynamic/x86_64: /s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/trunk/projects/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
:info:build /s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/build/Release+Debug+Asserts/bin/clang -std=c++11 -fno-exceptions -fPIC -funwind-tables -I/s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/trunk/projects/compiler-rt/lib -I/s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/trunk/projects/compiler-rt/include -arch x86_64 -fvisibility=hidden -DVISIBILITY_HIDDEN -Wall -Werror -O3 -fomit-frame-pointer -mios-simulator-version-min=7.0 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk -fno-builtin -gline-tables-only -stdlib=libc++ -DMAC_INTERPOSE_FUNCTIONS=1 -DASAN_DYNAMIC=1 -c -o /s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/build/tools/clang/runtime/compiler-rt/clang_darwin/asan_iossim_dynamic/x86_64/SubDir.lib__sanitizer_common/sanitizer_mac.o /s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/trunk/projects/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc
:info:build In file included from /s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/trunk/projects/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc:43:
:info:build In file included from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk/usr/include/mach/mach.h:67:
:info:build In file included from /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk/usr/include/mach/mach_interface.h:49:
:info:build /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk/usr/include/mach/task.h:31:10: fatal error: 'mach/x86_64/task.h' file not found
:info:build #include <mach/x86_64/task.h>
:info:build          ^
:info:build 1 error generated.
:info:build make[4]: *** [/s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/build/tools/clang/runtime/compiler-rt/clang_darwin/asan_iossim_dynamic/x86_64/SubDir.lib__sanitizer_common/sanitizer_mac.o] Error 1
:info:build make[4]: *** Waiting for unfinished jobs....
:info:build make[4]: Leaving directory `/s/macports_build/osx-10.8_xcode-4.4/_opt_llvm-mp_var_macports_sources_rsync.macports.org_release_tarballs_ports_lang_llvm-3.7/clang-3.7/work/trunk/projects/compiler-rt'
:info:build make[3]: *** [BuildRuntimeLibraries] Error 2