[DAGCombiner] crash since 7e72caf

[JonPsson1]

Bisected to "[SelectionDAG] Add MaskedValueIsZero check to allow folding of zero extended variables we know are safe to extend (#85573)" 7e72caf.

llc -mcpu=z10 -O3  tc_dagcomb_zext.ll

APInt.h:1347: void llvm::APInt::setBits(unsigned int, unsigned int): Assertion `loBit <= BitWidth && "loBit out of range"' failed.
...
#10 0x00000000029f46d6 (anonymous namespace)::DAGCombiner::visitZERO_EXTEND
...

@g_0 = external dso_local local_unnamed_addr global i16, align 2
@g_1 = external dso_local local_unnamed_addr global i32, align 4
@g_2 = external dso_local local_unnamed_addr global i32, align 4

define void @func() {
  store i32 41, ptr @g_1, align 4
  %1 = load i32, ptr @g_1, align 4
  %2 = load i16, ptr @g_0, align 2
  %3 = zext i16 %2 to i32
  %4 = shl i32 %3, %1
  %5 = zext i32 %4 to i64
  %6 = shl i64 %5, 48
  %7 = ashr exact i64 %6, 48
  %8 = or i64 %7, 0
  %9 = sext i32 %1 to i64
  %10 = icmp sge i64 %8, %9
  %11 = zext i1 %10 to i32
  %12 = or i32 0, %11
  store i32 %12, ptr @g_2, align 4
  ret void
}