This instruction is just a control flow marker - it should not
actually exist in the object file. Unfortunately, nothing catches
it before it gets to AsmPrinter. If integrated assembler is used,
it's considered to be a normal 4-byte instruction, and emitted as
an all-0 word, crashing the program. With external assembler,
a comment is emitted.
Fixed by setting Size to 0 and handling it in MCCodeEmitter - this
means the comment will still be emitted if integrated assembler
is not used.
This broke an ASan test, which has been disabled for a long time
as a result (see the discussion on D19657). We can reenable it
once this lands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@267943 91177308-0d34-0410-b5e6-96231b3b80d8
b527cb338d