Turn const_caller_location from a query to a hook

compiler/rustc_middle/src/hooks/mod.rs

@@ -67,4 +67,7 @@ declare_hooks! {
     /// Tries to destructure an `mir::Const` ADT or array into its variant index
     /// and its field values. This should only be used for pretty printing.
     hook try_destructure_mir_constant_for_diagnostics(val: mir::ConstValue<'tcx>, ty: Ty<'tcx>) -> Option<mir::DestructuredConstant<'tcx>>;
+
+    /// Getting a &core::panic::Location referring to a span.
+    hook const_caller_location(file: rustc_span::Symbol, line: u32, col: u32) -> mir::ConstValue<'tcx>;
 }

compiler/rustc_middle/src/mir/consts.rs

@@ -590,12 +590,12 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn span_as_caller_location(self, span: Span) -> ConstValue<'tcx> {
         let topmost = span.ctxt().outer_expn().expansion_cause().unwrap_or(span);
         let caller = self.sess.source_map().lookup_char_pos(topmost.lo());
-        self.const_caller_location((
+        self.const_caller_location(
             rustc_span::symbol::Symbol::intern(
                 &caller.file.name.for_codegen(&self.sess).to_string_lossy(),
             ),
             caller.line as u32,
             caller.col_display as u32 + 1,
-        ))
+        )
     }
 }

compiler/rustc_middle/src/query/mod.rs

@@ -1101,10 +1101,6 @@ rustc_queries! {
         desc { "destructuring type level constant"}
     }
 
-    query const_caller_location(key: (rustc_span::Symbol, u32, u32)) -> mir::ConstValue<'tcx> {
-        desc { "getting a &core::panic::Location referring to a span" }
-    }
-
     // FIXME get rid of this with valtrees
     query lit_to_const(
         key: LitToConstInput<'tcx>