FileCheck switch_int.

tests/mir-opt/const_prop/switch_int.rs

@@ -1,13 +1,20 @@
-// skip-filecheck
 // unit-test: ConstProp
 // compile-flags: -Zmir-enable-passes=+SimplifyConstCondition-after-const-prop
 // EMIT_MIR_FOR_EACH_PANIC_STRATEGY
+
 #[inline(never)]
 fn foo(_: i32) { }
 
 // EMIT_MIR switch_int.main.ConstProp.diff
 // EMIT_MIR switch_int.main.SimplifyConstCondition-after-const-prop.diff
 fn main() {
+    // CHECK-LABEL: fn main(
+    // CHECK: bb0: {
+    // CHECK-NOT: switchInt(
+    // CHECK: goto -> [[bb:bb.*]];
+    // CHECK: [[bb]]: {
+    // CHECK-NOT: _0 = foo(const -1_i32)
+    // CHECK: _0 = foo(const 0_i32)
     match 1 {
         1 => foo(0),
         _ => foo(-1),