Add crash tests.

Author: cjgillot

tests/crashes/139872.rs

@@ -0,0 +1,12 @@
+//@ known-bug: #139872
+
+enum E {
+    V16(u16),
+    V32(u32),
+}
+
+static C: (E, u16, str) = (E::V16(0xDEAD), 0x600D, 0xBAD);
+
+pub fn main() {
+    let (_, n, _) = C;
+}

tests/crashes/140332.rs

@@ -0,0 +1,7 @@
+//@ known-bug: #140332
+
+static mut S: [i8] = ["Some thing"; 1];
+
+fn main() {
+    assert_eq!(S, [0; 1]);
+}