[TableGen] Fix instantiating multiclass in foreach

If multiclass argument comes from loop varaible and argument is record type,
it will not recognize the type. This patch ensures that loop variables are
resolved correctly.

Differential Revision: https://reviews.llvm.org/D95308

llvm/lib/TableGen/TGParser.cpp

@@ -3524,8 +3524,8 @@ bool TGParser::ParseDefm(MultiClass *CurMultiClass) {
 
     Substs.emplace_back(QualifiedNameOfImplicitName(MC), DefmName);
 
-    if (resolve(MC->Entries, Substs, CurMultiClass == nullptr, &NewEntries,
-                &SubClassLoc))
+    if (resolve(MC->Entries, Substs, !CurMultiClass && Loops.empty(),
+                &NewEntries, &SubClassLoc))
       return true;
 
     if (!consume(tgtok::comma))

llvm/test/TableGen/foreach-multiclass.td

@@ -57,6 +57,9 @@
 // CHECK:     def F2_2_1
 // CHECK-NOT: def F2_2_2
 
+// CHECK: def G0
+// CHECK: def H0_G0_0
+
 multiclass A<int x> {
   foreach i = [0, 1] in {
     def NAME#i {
@@ -116,3 +119,20 @@ multiclass F<list<int> lst> {
 defm F0 : F<[]>;
 defm F1 : F<[0]>;
 defm F2 : F<[0, 1, 2]>;
+
+// If multiclass argument comes from loop variable,
+// and field of argument is placed at foreach statement,
+// the record field must be resolved correctly.
+class G {
+  list<int> val = [0];
+}
+
+multiclass H<G g> {
+  foreach n = g.val in
+    def _#g#_#n;
+}
+
+def G0 : G;
+
+foreach g = [G0] in
+  defm H0 : H<g>;