Move additional source location info behind -Z option

compiler/rustc_session/src/options.rs

@@ -1907,6 +1907,8 @@ options! {
     #[rustc_lint_opt_deny_field_access("use `Session::mir_opt_level` instead of this field")]
     mir_opt_level: Option<usize> = (None, parse_opt_number, [TRACKED],
         "MIR optimization level (0-4; default: 1 in non optimized builds and 2 in optimized builds)"),
+    more_source_locations_in_debuginfo: bool = (false, parse_bool, [UNTRACKED],
+        "include additional source file and line number information in debuginfo (default: no)"),
     move_size_limit: Option<usize> = (None, parse_opt_number, [TRACKED],
         "the size at which the `large_assignments` lint starts to be emitted"),
     mutable_noalias: bool = (true, parse_bool, [TRACKED],