Summary:
The assembler currently does not check the branch target for CBZ/CBNZ
instructions, which only permit branching forwards with a positive offset. This
adds validation for the branch target to ensure negative PC-relative offsets are
not encoded into the instruction, whether specified as a literal or as an
assembler symbol.
Reviewers: rengolin, t.p.northover
Subscribers: llvm-commits, rengolin
Differential Revision: https://reviews.llvm.org/D23312
llvm-svn: 278788
15ed7ec5aa