keep const blocks around

Author: BoxyUwU

tests/source/issue-6788.rs

@@ -0,0 +1,7 @@
+fn foo() {
+    let a = [(); const { let x = 1; x }];
+}
+
+fn foo() {
+    let x = [(); const { 1 }];
+}

tests/target/issue-6788.rs

@@ -0,0 +1,10 @@
+fn foo() {
+    let a = [(); const {
+        let x = 1;
+        x
+    }];
+}
+
+fn foo() {
+    let x = [(); const { 1 }];
+}