[TableGen] Make the ambiguous match debug messages from the AsmMatcherEmitter slightly more useful.

Don't report ambiguous matches on different variants. Print the variant number in the output.

llvm-svn: 321938
diff --git a/llvm/utils/TableGen/AsmMatcherEmitter.cpp b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
index f2d304b..b3b670b 100644
--- a/llvm/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
@@ -620,6 +620,10 @@
     if (Mnemonic != RHS.Mnemonic)
       return false;
 
+    // Different variants can't conflict.
+    if (AsmVariantID != RHS.AsmVariantID)
+      return false;
+
     // The number of operands is unambiguous.
     if (AsmOperands.size() != RHS.AsmOperands.size())
       return false;
@@ -770,6 +774,8 @@
 LLVM_DUMP_METHOD void MatchableInfo::dump() const {
   errs() << TheDef->getName() << " -- " << "flattened:\"" << AsmString <<"\"\n";
 
+  errs() << "  variant: " << AsmVariantID << "\n";
+
   for (unsigned i = 0, e = AsmOperands.size(); i != e; ++i) {
     const AsmOperand &Op = AsmOperands[i];
     errs() << "  op[" << i << "] = " << Op.Class->ClassName << " - ";