move passing stage1 compile error tests to stage2

test/cases/compile_errors/integer_underflow_error.zig

@@ -0,0 +1,9 @@
+export fn entry() void {
+    _ = @intToPtr(*anyopaque, ~@as(usize, @import("std").math.maxInt(usize)) - 1);
+}
+
+// error
+// backend=stage2
+// target=native
+//
+// :2:78: error: overflow of integer type 'usize' with value '-1'