If multiple instances of the -arm-implicit-it option is passed to
the backend, it errors out.
Also fix cases where there are multiple -Wa,-mimplicit-it; the existing
tests indicate that the last one specified takes effect, while in
practice it passed double options, which didn't work as intended.
Differential Revision: https://reviews.llvm.org/D102812
This reverts commit 2919222d80.
That commit broke backwards compatibility. Additionally, the
replacement, -Wa,-mimplicit-it, isn't yet supported by any stable
release of Clang.
See D102812 for a fix for the error cases when callers specify both
-mimplicit-it and -Wa,-mimplicit-it.
This is a GNU as and Clang cc1as option, not a GCC option.
Users should specify `-Wa,-mimplicit-it=` instead.
Note: mixing the -m option and the -Wa, option doesn't work
`-Wa,-mimplicit-it=never -mimplicit-it=always` =>
`clang (LLVM option parsing): for the --arm-implicit-it option: may only occur zero or one times!`
Reviewed By: nickdesaulniers, raj.khem
Differential Revision: https://reviews.llvm.org/D102568