add tests

cranelift/filetests/filetests/peepmatic/simplify64.clif

@@ -324,3 +324,17 @@ block0(v0: i32):
 ; nextln:    v1 = iadd_imm v0, 42
 ; nextln:    nop
 ; nextln:    return v2
+
+function %bxor_imm_32(i32) -> i32 {
+block0(v0: i32):
+    v1 = bxor_imm v0, -1
+    ; check: bnot v0
+    return v1
+}
+
+function %bxor_imm_64(i64) -> i64 {
+block0(v0: i64):
+    v1 = bxor_imm v0, -1
+    ; check: bnot v0
+    return v1
+}