Add MIR test

Author: sinkuu

src/test/mir-opt/match_test.rs

@@ -0,0 +1,85 @@
+// Make sure redundant testing paths in `match` expressions are sorted out.
+
+#![feature(exclusive_range_pattern)]
+
+fn main() {
+    let x = 3;
+    let b = true;
+
+    // When `(0..=10).contains(x) && !b`, we should jump to the last arm
+    // without testing two other candidates.
+    match x {
+        0..10 if b => 0,
+        10..=20 => 1,
+        -1 => 2,
+        _ => 3,
+    };
+}
+
+// END RUST SOURCE
+// START rustc.main.SimplifyCfg-initial.after.mir
+//    bb0: {
+//        ...
+//        _4 = Le(const 0i32, _1);
+//        switchInt(move _4) -> [false: bb10, otherwise: bb11];
+//    }
+//    bb1: {
+//        _3 = const 0i32;
+//        goto -> bb16;
+//    }
+//    bb2: {
+//        _3 = const 1i32;
+//        goto -> bb16;
+//    }
+//    bb3: {
+//        _3 = const 2i32;
+//        goto -> bb16;
+//    }
+//    bb4: {
+//        _3 = const 3i32;
+//        goto -> bb16;
+//    }
+//    bb5: {
+//        falseEdges -> [real: bb12, imaginary: bb6];
+//    }
+//    bb6: {
+//        falseEdges -> [real: bb2, imaginary: bb7];
+//    }
+//    bb7: {
+//        falseEdges -> [real: bb3, imaginary: bb8];
+//    }
+//    bb8: {
+//        falseEdges -> [real: bb4, imaginary: bb9];
+//    }
+//    bb9: {
+//        unreachable;
+//    }
+//    bb10: {
+//        _7 = Le(const 10i32, _1);
+//        switchInt(move _7) -> [false: bb14, otherwise: bb15];
+//    }
+//    bb11: {
+//        _5 = Lt(_1, const 10i32);
+//        switchInt(move _5) -> [false: bb10, otherwise: bb5];
+//    }
+//    bb12: {
+//        StorageLive(_6);
+//        _6 = _2;
+//        switchInt(move _6) -> [false: bb13, otherwise: bb1];
+//    }
+//    bb13: {
+//        falseEdges -> [real: bb8, imaginary: bb6];
+//    }
+//    bb14: {
+//        switchInt(_1) -> [-1i32: bb7, otherwise: bb8];
+//    }
+//    bb15: {
+//        _8 = Le(_1, const 20i32);
+//        switchInt(move _8) -> [false: bb14, otherwise: bb6];
+//    }
+//    bb16: {
+//        StorageDead(_6);
+//        ...
+//        return;
+//    }
+// END rustc.main.SimplifyCfg-initial.after.mir