gccrs: Fix ICE on raw reference

This patch adds support for raw references which enforce the pointer
type away from a reference type.

Fixes Rust-GCC#3667

gcc/rust/ChangeLog:

	* backend/rust-compile-base.cc (HIRCompileBase::address_expression): allow optional type
	* backend/rust-compile-base.h: update prototype
	* backend/rust-compile-expr.cc (CompileExpr::visit): update borrow expr
	* backend/rust-compile-extern.h: remove unused debug
	* backend/rust-compile-resolve-path.cc (HIRCompileBase::query_compile): update usage
	* hir/rust-ast-lower-expr.cc (ASTLoweringExpr::visit): lower raw ref
	* hir/tree/rust-hir-expr.cc (BorrowExpr::BorrowExpr): add flag for raw ref
	* hir/tree/rust-hir-expr.h (class BorrowExpr): add new raw ref field
	* typecheck/rust-hir-type-check-expr.cc (TypeCheckExpr::visit): add handle for raw ref

gcc/testsuite/ChangeLog:

	* rust/compile/issue-3667.rs: New test.

Signed-off-by: Philip Herron <herron.philip@googlemail.com>

3 files changed, 9 insertions, 10 deletions

diff --git a/gcc/rust/hir/rust-ast-lower-expr.cc b/gcc/rust/hir/rust-ast-lower-expr.cc
index d0d004e..575eea6 100644
--- a/gcc/rust/hir/rust-ast-lower-expr.cc
+++ b/gcc/rust/hir/rust-ast-lower-expr.cc
@@ -633,9 +633,6 @@ ASTLoweringExpr::visit (AST::ContinueExpr &expr)
 void
 ASTLoweringExpr::visit (AST::BorrowExpr &expr)
 {
-  if (expr.is_raw_borrow ())
-    rust_unreachable ();
-
   HIR::Expr *borrow_lvalue
     = ASTLoweringExpr::translate (expr.get_borrowed_expr ());
 
@@ -646,8 +643,8 @@ ASTLoweringExpr::visit (AST::BorrowExpr &expr)
 
   auto *borrow_expr
     = new HIR::BorrowExpr (mapping, std::unique_ptr<HIR::Expr> (borrow_lvalue),
-			   expr.get_mutability (), expr.get_outer_attrs (),
-			   expr.get_locus ());
+			   expr.get_mutability (), expr.is_raw_borrow (),
+			   expr.get_outer_attrs (), expr.get_locus ());
 
   if (expr.get_is_double_borrow ())
     {
@@ -659,8 +656,8 @@ ASTLoweringExpr::visit (AST::BorrowExpr &expr)
       borrow_expr
 	= new HIR::BorrowExpr (mapping,
 			       std::unique_ptr<HIR::Expr> (borrow_expr),
-			       expr.get_mutability (), expr.get_outer_attrs (),
-			       expr.get_locus ());
+			       expr.get_mutability (), expr.is_raw_borrow (),
+			       expr.get_outer_attrs (), expr.get_locus ());
     }
 
   translated = borrow_expr;
diff --git a/gcc/rust/hir/tree/rust-hir-expr.cc b/gcc/rust/hir/tree/rust-hir-expr.cc
index 2ded789..bb7ebfb 100644
--- a/gcc/rust/hir/tree/rust-hir-expr.cc
+++ b/gcc/rust/hir/tree/rust-hir-expr.cc
@@ -81,10 +81,10 @@ OperatorExpr::operator= (OperatorExpr const &other)
 
 BorrowExpr::BorrowExpr (Analysis::NodeMapping mappings,
 			std::unique_ptr<Expr> borrow_lvalue, Mutability mut,
-			AST::AttrVec outer_attribs, location_t locus)
+			bool raw, AST::AttrVec outer_attribs, location_t locus)
   : OperatorExpr (std::move (mappings), std::move (borrow_lvalue),
 		  std::move (outer_attribs), locus),
-    mut (mut)
+    mut (mut), raw (raw)
 {}
 
 DereferenceExpr::DereferenceExpr (Analysis::NodeMapping mappings,
diff --git a/gcc/rust/hir/tree/rust-hir-expr.h b/gcc/rust/hir/tree/rust-hir-expr.h
index 4603927..bd2f9d4 100644
--- a/gcc/rust/hir/tree/rust-hir-expr.h
+++ b/gcc/rust/hir/tree/rust-hir-expr.h
@@ -199,12 +199,13 @@ public:
 class BorrowExpr : public OperatorExpr
 {
   Mutability mut;
+  bool raw;
 
 public:
   std::string as_string () const override;
 
   BorrowExpr (Analysis::NodeMapping mappings,
-	      std::unique_ptr<Expr> borrow_lvalue, Mutability mut,
+	      std::unique_ptr<Expr> borrow_lvalue, Mutability mut, bool raw,
 	      AST::AttrVec outer_attribs, location_t locus);
 
   void accept_vis (HIRFullVisitor &vis) override;
@@ -212,6 +213,7 @@ public:
 
   Mutability get_mut () const { return mut; }
   bool is_mut () const { return mut == Mutability::Mut; }
+  bool is_raw_borrow () const { return raw; }
 
 protected:
   /* Use covariance to implement clone function as returning this object rather