[SelectionDAG] Fix the assertion failure in Release build after llvm#91747

In llvm#91747, we change the SDNode from `X86ISD::SUB` (FROM) to
`X86ISD::CCMP` (TO) in the DAGCombine. The value type of X86ISD::SUB
can be `i8, i32` while the value type of X86ISD::CCMP is `i32`.

That means the `SDValue(FROM, 0)` is unused and may be removed.
However, `transferDbgValues` assumes the value is not null, which is
called by `ReplaceAllUsesWith(SDNode *, const SDValue *)`.
So we need to check if the value has any use before calling the function.

Note: We already have same check in `ReplaceAllUsesWith(SDNode *, SDNode *)`.

This fix the error

```
SelectionDAG.cpp:10942: void
llvm::SelectionDAG::transferDbgValues(llvm::SDValue, llvm::SDValue,
unsigned int, unsigned int, bool): Assertion `FromNode && ToNode &&
"Can't modify dbg values"' failed.
```

for tests

llvm/test/CodeGen/X86/apx/ccmp.ll
llvm/test/CodeGen/X86/apx/ctest.ll

in Release build when LLVM_ENABLE_ASSERTIONS is on.

Author: KanRobert

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -11293,10 +11293,12 @@ void SelectionDAG::ReplaceAllUsesWith(SDNode *From, const SDValue *To) {
     return ReplaceAllUsesWith(SDValue(From, 0), To[0]);
 
   for (unsigned i = 0, e = From->getNumValues(); i != e; ++i) {
-    // Preserve Debug Info.
-    transferDbgValues(SDValue(From, i), To[i]);
-    // Preserve extra info.
-    copyExtraInfo(From, To[i].getNode());
+    if (From->hasAnyUseOfValue(i)) {
+      // Preserve Debug Info.
+      transferDbgValues(SDValue(From, i), To[i]);
+      // Preserve extra info.
+      copyExtraInfo(From, To[i].getNode());
+    }
   }
 
   // Iterate over just the existing users of From. See the comments in