[llvm] [NFC][DecoderEmitter] Predicate generation code cleanup (PR #158140)

[Sergei Barannikov via llvm-commits]

================
@@ -1269,15 +1253,13 @@ unsigned DecoderTableBuilder::getPredicateIndex(StringRef Predicate) const {
 }
 
 void DecoderTableBuilder::emitPredicateTableEntry(unsigned EncodingID) const {
-  if (!doesOpcodeNeedPredicate(EncodingID))
-    return;
-
   // Build up the predicate string.
   SmallString<256> Predicate;
   // FIXME: emitPredicateMatch() functions can take a buffer directly rather
   // than a stream.
   raw_svector_ostream PS(Predicate);
-  emitPredicateMatch(PS, EncodingID);
+  if (!emitPredicateMatch(PS, EncodingID))
+    return;
----------------
s-barannikov wrote:

`Predicate.empty()` could also work

https://github.com/llvm/llvm-project/pull/158140