Created using spr 1.3.4

[skip ci]

This reverts commit 7eaf4708098c216bf432fc7e0bc79c3771e793a4.

Reason: buildbot breakage (e.g.,
https://lab.llvm.org/buildbot/#/builders/144/builds/14299/steps/6/logs/FAIL__Clang__ubsan-trap-debugloc_c)

Fixes #119952

I missed that FalseCnt for each Case was used to calculate percentage in
the SwitchStmt. At the moment I resurrect them.

In `!HasDefaultCase`, the pair of Counters shall be `[CaseCountSum,
FalseCnt]`. (Reversal of before #112694)
I think it can be considered as the False count on SwitchStmt.

FalseCnt shall be folded (same as current impl) in the coming
SingleByteCoverage changes, since percentage would not make sense.

'-mllvm -ubsan-unique-traps'
(https://github.com/llvm/llvm-project/pull/65972) applies to all UBSan
checks. This patch introduces -fsanitize-merge (defaults to on,
maintaining the status quo behavior) and -fno-sanitize-merge (equivalent
to '-mllvm -ubsan-unique-traps'), with the option to selectively
applying non-merged handlers to a subset of UBSan checks (e.g.,
-fno-sanitize-merge=bool,enum).

N.B. we do not use "trap" in the argument name since
https://github.com/llvm/llvm-project/pull/119302 has generalized
-ubsan-unique-traps to work for non-trap modes (min-rt and regular rt).

This patch does not remove the -ubsan-unique-traps flag; that will
override -f(no-)sanitize-merge.

Created using spr 1.3.4

[skip ci]

The arguments to this are the same as for the 'wait' clause, so this
reuses all of that infrastructure. So all this has to do is support a
pair of clauses that are already implemented (if and async), plus create
an AST node.  This patch does so, and adds proper testing.

Support true16 format for v_minmax/maxmin_f16 in MC.

Since we are replacing `v_minmax/maxmin_f16` to `v_minmax/maxmin_f16_t16
/ v_minmax/maxmin_f16_fake16` in Post-GFX11, have to update the CodeGen
pattern for `v_minmax/maxmin_f16` to get CodeGen test passing.

Created using spr 1.3.4

[skip ci]