[PowerPC] Ensure that the TOC reload directly follows bctrl on PPC64

On non-Darwin PPC64, the TOC reload needs to come directly after the bctrl
instruction (for indirect calls) because the 'bctrl/ld 2, 40(1)' instruction
sequence is interpreted by the unwinding code in libgcc. To make sure these
occur as a pair, as with other pairings interpreted by the linker, fuse the two
instructions into one instruction (for code generation only).

In the future, we might wish to do this by emitting CFI directives instead,
but this solution is simpler, and mirrors what GCC does. Additional discussion
on this point is contained in the PR.

Fixes PR22015.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224788 91177308-0d34-0410-b5e6-96231b3b80d8
[asan] change the coverage collection scheme so that we can easily emit coverage for the entire process as a single bit set, and if coverage_bitset=1 actually emit that bitset

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224789 91177308-0d34-0410-b5e6-96231b3b80d8
Add printing the LC_THREAD load commands with llvm-objdump’s -private-headers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224792 91177308-0d34-0410-b5e6-96231b3b80d8