crashes: add test for #131451

Author: matthiaskrgr

tests/crashes/131451.rs

@@ -0,0 +1,9 @@
+//@ known-bug: #131451
+//@ needs-rustc-debug-assertions
+//@ compile-flags: -Zmir-enable-passes=+GVN -Zmir-enable-passes=+JumpThreading --crate-type=lib
+
+pub fn fun(terminate: bool) {
+    while true {}
+
+    while !terminate {}
+}