Empty macro arguments at the end of the list should be as-if not specified at
all, but those in the middle of the list need to be kept so as not to screw
up the positional numbering. E.g.:
.macro foo
foo_-bash___:
nop
.endm
foo 1, 2, 3, 4
foo 1, , 3, 4
Should create two labels, "foo_1_2_3_4" and "foo_1__3_4".
rdar://11948769
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161002 91177308-0d34-0410-b5e6-96231b3b80d8
