Add let !eq in submulticlass test.

Author: jofrn

llvm/test/TableGen/submulticlass-leteq.td

@@ -0,0 +1,21 @@
+// RUN: llvm-tblgen %s | FileCheck %s
+// XFAIL: vg_leak
+// CHECK:      def X0 { // C
+// CHECK-NEXT:   bit x = 1;
+// CHECK-NEXT: }
+// CHECK-NEXT: def X1 { // C
+// CHECK-NEXT:   bit x = 0;
+// CHECK-NEXT: }
+class C {
+  bit x;
+}
+multiclass M0<bits<8> Val> {
+  let x = !eq(Val, !cast<bits<8>>(-1)) in def NAME : C;
+}
+multiclass M1<bits<8> Val> {
+  let x = !eq(Val, -1) in def NAME : C;
+}
+multiclass M2_0 : M0<-1>;
+multiclass M2_1 : M1<-1>;
+defm X0 : M2_0;
+defm X1 : M2_1;