Update build system for better Clang behavior on Mac.

Change-Id: I1813954681b670807d7e3faaf6d5f5a769cc5f2e
Switch to new host prebuilt x86_64-linux-glibc2.11-4.6

Change-Id: I763398d523bf4851a13722f72b12ec69d7a4bb4f
Build changes necessary for LLVM 3.5 switch.

Change-Id: Icb6065daada7cb1d7425206830a4ef9e23454c03

Conflicts:
	core/clang/arm.mk
Merge "Update build system for better Clang behavior on Mac." into idea133
Merge changes I40c7226d,I763398d5 into idea133

* changes:
  Build changes necessary for LLVM 3.5 switch.
  Switch to new host prebuilt x86_64-linux-glibc2.11-4.6
Remove tblgen and clang-tblgen from prebuilts.

Change-Id: I89fb74da5a516d0f768f72518a401216f8a5b1a8
(cherry picked from commit 75b58cc827faad56517181960f81f5b4bd8a08f0)
(cherry picked from commit da522500c4e76106dec5143834edca681726b5b7)
Merge "Remove tblgen and clang-tblgen from prebuilts." into idea133
Temporarily disable emulator build on MacOS X.

Change-Id: I3740de7ef41520f6079a1dc48910e39e64f4a8b2
Merge "Temporarily disable emulator build on MacOS X." into idea133
Remove SDK Tools from platform builds.

Change-Id: I44de4f55b66de1df52a37b29bfa7d81262c8be1b
Merge "Remove SDK Tools from platform builds." into idea133