[Coverity] Fix unchecked return value, NFC

Author: phoebewang

llvm/lib/CodeGen/MIRParser/MIParser.cpp

@@ -470,7 +470,7 @@ class MIParser {
   bool parseJumpTableIndexOperand(MachineOperand &Dest);
   bool parseExternalSymbolOperand(MachineOperand &Dest);
   bool parseMCSymbolOperand(MachineOperand &Dest);
-  bool parseMDNode(MDNode *&Node);
+  [[nodiscard]] bool parseMDNode(MDNode *&Node);
   bool parseDIExpression(MDNode *&Expr);
   bool parseDILocation(MDNode *&Expr);
   bool parseMetadataOperand(MachineOperand &Dest);
@@ -3471,7 +3471,8 @@ bool MIParser::parseHeapAllocMarker(MDNode *&Node) {
   assert(Token.is(MIToken::kw_heap_alloc_marker) &&
          "Invalid token for a heap alloc marker!");
   lex();
-  parseMDNode(Node);
+  if (parseMDNode(Node))
+    return true;
   if (!Node)
     return error("expected a MDNode after 'heap-alloc-marker'");
   if (Token.isNewlineOrEOF() || Token.is(MIToken::coloncolon) ||
@@ -3487,7 +3488,8 @@ bool MIParser::parsePCSections(MDNode *&Node) {
   assert(Token.is(MIToken::kw_pcsections) &&
          "Invalid token for a PC sections!");
   lex();
-  parseMDNode(Node);
+  if (parseMDNode(Node))
+    return true;
   if (!Node)
     return error("expected a MDNode after 'pcsections'");
   if (Token.isNewlineOrEOF() || Token.is(MIToken::coloncolon) ||