coverage: Tweak FileCheck directives in a mir-opt test

Author: Zalathar

tests/mir-opt/coverage/instrument_coverage.bar.InstrumentCoverage.diff

@@ -4,8 +4,8 @@
   fn bar() -> bool {
       let mut _0: bool;
 
-+     coverage body span: $DIR/instrument_coverage.rs:19:18: 21:2 (#0)
-+     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:19:1: 21:2 (#0);
++     coverage body span: $DIR/instrument_coverage.rs:29:18: 31:2 (#0)
++     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:29:1: 31:2 (#0);
 + 
       bb0: {
 +         Coverage::CounterIncrement(0);

tests/mir-opt/coverage/instrument_coverage.main.InstrumentCoverage.diff

@@ -7,13 +7,13 @@
       let mut _2: bool;
       let mut _3: !;
 
-+     coverage body span: $DIR/instrument_coverage.rs:10:11: 16:2 (#0)
++     coverage body span: $DIR/instrument_coverage.rs:14:11: 20:2 (#0)
 +     coverage ExpressionId(0) => Expression { lhs: Counter(1), op: Subtract, rhs: Counter(0) };
-+     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:10:1: 10:11 (#0);
-+     coverage Code(Counter(1)) => $DIR/instrument_coverage.rs:12:12: 12:17 (#0);
-+     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:13:13: 13:18 (#0);
-+     coverage Code(Expression(0)) => $DIR/instrument_coverage.rs:14:10: 14:10 (#0);
-+     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:16:2: 16:2 (#0);
++     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:14:1: 14:11 (#0);
++     coverage Code(Counter(1)) => $DIR/instrument_coverage.rs:16:12: 16:17 (#0);
++     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:17:13: 17:18 (#0);
++     coverage Code(Expression(0)) => $DIR/instrument_coverage.rs:18:10: 18:10 (#0);
++     coverage Code(Counter(0)) => $DIR/instrument_coverage.rs:20:2: 20:2 (#0);
 + 
       bb0: {
 +         Coverage::CounterIncrement(0);

tests/mir-opt/coverage/instrument_coverage.rs

@@ -6,7 +6,11 @@
 //@ compile-flags: -Cinstrument-coverage -Zno-profiler-runtime
 
 // EMIT_MIR instrument_coverage.main.InstrumentCoverage.diff
-// EMIT_MIR instrument_coverage.bar.InstrumentCoverage.diff
+// CHECK-LABEL: fn main()
+// CHECK: coverage body span:
+// CHECK: coverage Code(Counter({{[0-9]+}})) =>
+// CHECK: bb0:
+// CHECK: Coverage::CounterIncrement
 fn main() {
     loop {
         if bar() {
@@ -15,14 +19,13 @@ fn main() {
     }
 }
 
+// EMIT_MIR instrument_coverage.bar.InstrumentCoverage.diff
+// CHECK-LABEL: fn bar()
+// CHECK: coverage body span:
+// CHECK: coverage Code(Counter({{[0-9]+}})) =>
+// CHECK: bb0:
+// CHECK: Coverage::CounterIncrement
 #[inline(never)]
 fn bar() -> bool {
     true
 }
-
-// CHECK:     coverage ExpressionId({{[0-9]+}}) =>
-// CHECK-DAG: coverage Code(Counter({{[0-9]+}})) =>
-// CHECK-DAG: coverage Code(Expression({{[0-9]+}})) =>
-// CHECK:     bb0:
-// CHECK-DAG: Coverage::ExpressionUsed({{[0-9]+}})
-// CHECK-DAG: Coverage::CounterIncrement({{[0-9]+}})