Change src/test to tests in source files, fix tidy and tests

Author: albertlarsan68

tests/ui/crashes/ice-6254.rs

@@ -1,4 +1,4 @@
-// originally from ./src/test/ui/pattern/usefulness/consts-opaque.rs
+// originally from ./tests/ui/pattern/usefulness/consts-opaque.rs
 // panicked at 'assertion failed: rows.iter().all(|r| r.len() == v.len())',
 // compiler/rustc_mir_build/src/thir/pattern/_match.rs:2030:5
 

tests/ui/crashes/ice-6255.rs

@@ -1,4 +1,4 @@
-// originally from rustc ./src/test/ui/macros/issue-78325-inconsistent-resolution.rs
+// originally from rustc ./tests/ui/macros/issue-78325-inconsistent-resolution.rs
 // inconsistent resolution for a macro
 
 macro_rules! define_other_core {

tests/ui/crashes/ice-6256.rs

@@ -1,4 +1,4 @@
-// originally from rustc ./src/test/ui/regions/issue-78262.rs
+// originally from rustc ./tests/ui/regions/issue-78262.rs
 // ICE: to get the signature of a closure, use substs.as_closure().sig() not fn_sig()
 #![allow(clippy::upper_case_acronyms)]