test: Add scope test.

test/vast/Conversion/FromHL/ToLLCF/for-a.c

@@ -2,6 +2,7 @@
 
 void fn()
 {
+    // CHECK: ll.scope {
     // CHECK: ll.scope {
     // CHECK-NEXT: ll.br ^bb1
 

test/vast/Conversion/scope-a.c

@@ -0,0 +1,24 @@
+// RUN: %vast-front -vast-emit-mlir-after=vast-hl-to-ll-cf %s -o %t.mlir
+// RUN: %file-check --input-file=%t.mlir %s -check-prefix=LL_CF
+
+void fn(int arg)
+{
+    // LL_CF: ll.scope {
+    // LL_CF:   [[V3:%[0-9]+]] = ll.initialize {{.*}} : (!hl.lvalue<si32>, si32) -> !hl.lvalue<si32>
+    // LL_CF:   ll.scope {
+    // LL_CF:     ll.cond_br {{.8}} : i1, ^bb1, ^bb2
+    // LL_CF:   ^bb1:  // pred: ^bb0
+    // LL_CF:     [[V9:%[0-9]+]] = hl.ref [[V3]] : (!hl.lvalue<si32>) -> !hl.lvalue<si32>
+    // LL_CF:     {{.*}} = hl.assign {{.*}} to [[V9]] : si32, !hl.lvalue<si32> -> si32
+    // LL_CF:     ll.br ^bb2
+    // LL_CF:   ^bb2:  // 2 preds: ^bb0, ^bb1
+    // LL_CF:     ll.scope_ret
+    // LL_CF:   }
+    // LL_CF: }
+    // LL_CF: ll.return {{.*}} : none
+    int a = 0;
+    {
+        if (arg != 0)
+            a = arg;
+    }
+}