Auto merge of #56240 - nikomatsakis:beta, r=pietroalbini

beta backports

Backported PRs:

- [x]  Avoid panic when matching function call #55742
- [x]  [beta] resolve: Implement edition hygiene for imports and absolute paths #56053

r? @ghost
cc @rust-lang/release

Author: bors

src/librustc/ty/context.rs

@@ -1484,15 +1484,8 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
     /// done with either: `-Ztwo-phase-borrows`, `#![feature(nll)]`,
     /// or by opting into an edition after 2015.
     pub fn two_phase_borrows(self) -> bool {
-        if self.features().nll || self.sess.opts.debugging_opts.two_phase_borrows {
-            return true;
-        }
-
-        match self.sess.edition() {
-            Edition::Edition2015 => false,
-            Edition::Edition2018 => true,
-            _ => true,
-        }
+        self.sess.rust_2018() || self.features().nll ||
+        self.sess.opts.debugging_opts.two_phase_borrows
     }
 
     /// What mode(s) of borrowck should we run? AST? MIR? both?

src/librustc/ty/item_path.rs

@@ -14,7 +14,6 @@ use ty::{self, DefIdTree, Ty, TyCtxt};
 use middle::cstore::{ExternCrate, ExternCrateSource};
 use syntax::ast;
 use syntax::symbol::{keywords, LocalInternedString, Symbol};
-use syntax_pos::edition::Edition;
 
 use std::cell::Cell;
 use std::fmt::Debug;
@@ -140,7 +139,7 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                         debug!("push_krate_path: name={:?}", name);
                         buffer.push(&name);
                     }
-                } else if self.sess.edition() == Edition::Edition2018 && !pushed_prelude_crate {
+                } else if self.sess.rust_2018() && !pushed_prelude_crate {
                     SHOULD_PREFIX_WITH_CRATE.with(|flag| {
                         // We only add the `crate::` keyword where appropriate. In particular,
                         // when we've not previously pushed a prelude crate to this path.