This reverts commit ab5e583327.
And statically link llvm libraries on host to remove dependency
on 32-bit llvm shared library which is not included in the prebuilt.
Bug: 22229391
Change-Id: I8210687655ee1809fd820ab2a6ca5dfaf3f9096d
Using llvm makes libbacktrace stops building for 32 bit on linux host x86_64.
This reverts commit c9c6b6ee77.
Change-Id: Ieb807db881d7bb3132cd09e25fd08c28766ca0a8