Move some tests to more reasonable directories - 2

Address comments

Update limits

src/test/ui/issues/issue-15881-model-lexer-dotdotdot.rs

@@ -1,38 +0,0 @@
-// run-pass
-#![allow(illegal_floating_point_literal_pattern)] // FIXME #41620
-#![allow(ellipsis_inclusive_range_patterns)]
-
-// regression test for the model lexer handling the DOTDOTDOT syntax (#15877)
-
-
-pub fn main() {
-    match 5_usize {
-      1_usize...5_usize => {}
-      _ => panic!("should match range"),
-    }
-    match 5_usize {
-      6_usize...7_usize => panic!("shouldn't match range"),
-      _ => {}
-    }
-    match 5_usize {
-      1_usize => panic!("should match non-first range"),
-      2_usize...6_usize => {}
-      _ => panic!("math is broken")
-    }
-    match 'c' {
-      'a'...'z' => {}
-      _ => panic!("should support char ranges")
-    }
-    match -3_isize {
-      -7...5 => {}
-      _ => panic!("should match signed range")
-    }
-    match 3.0f64 {
-      1.0...5.0 => {}
-      _ => panic!("should match float range")
-    }
-    match -1.5f64 {
-      -3.6...3.6 => {}
-      _ => panic!("should match negative float range")
-    }
-}