add mir dump test

Author: ericmarkmartin

tests/mir-opt/building/issue_110508.rs

@@ -0,0 +1,13 @@
+// EMIT_MIR issue_110508.{impl#0}-BAR1.built.after.mir
+// EMIT_MIR issue_110508.{impl#0}-BAR2.built.after.mir
+
+enum Foo {
+    Bar(()),
+}
+
+impl Foo {
+    const BAR1: Foo = Foo::Bar(());
+    const BAR2: Foo = Self::Bar(());
+}
+
+fn main() {}

tests/mir-opt/building/issue_110508.{impl#0}-BAR1.built.after.mir

@@ -0,0 +1,14 @@
+// MIR for `<impl at $DIR/issue_110508.rs:8:1: 8:9>::BAR1` after built
+
+const <impl at $DIR/issue_110508.rs:8:1: 8:9>::BAR1: Foo = {
+    let mut _0: Foo;
+    let mut _1: ();
+
+    bb0: {
+        StorageLive(_1);
+        _1 = ();
+        _0 = Foo::Bar(move _1);
+        StorageDead(_1);
+        return;
+    }
+}

tests/mir-opt/building/issue_110508.{impl#0}-BAR2.built.after.mir

@@ -0,0 +1,14 @@
+// MIR for `<impl at $DIR/issue_110508.rs:8:1: 8:9>::BAR2` after built
+
+const <impl at $DIR/issue_110508.rs:8:1: 8:9>::BAR2: Foo = {
+    let mut _0: Foo;
+    let mut _1: ();
+
+    bb0: {
+        StorageLive(_1);
+        _1 = ();
+        _0 = Foo::Bar(move _1);
+        StorageDead(_1);
+        return;
+    }
+}