hir: simplify is_range_literal

This commit simplifies `is_range_literal` by checking for
`QPath::LangItem` containing range-related lang items, rather than using
a heuristic.

Co-authored-by: Matthew Jasper <mjjasper1@gmail.com>
Signed-off-by: David Wood <david@davidtw.co>

src/test/ui/range/range-1.stderr

@@ -17,9 +17,13 @@ error[E0277]: the size for values of type `[{integer}]` cannot be known at compi
    |
 LL |     let range = *arr..;
    |                 ^^^^^^ doesn't have a size known at compile-time
+   | 
+  ::: $SRC_DIR/core/src/ops/range.rs:LL:COL
+   |
+LL | pub struct RangeFrom<Idx> {
+   |                      --- required by this bound in `std::ops::RangeFrom`
    |
    = help: the trait `std::marker::Sized` is not implemented for `[{integer}]`
-   = note: required by `std::ops::RangeFrom`
 
 error: aborting due to 3 previous errors