[COMMITTED 152/220] gccrs: return error node when this fails during constexpr case

[arthur . cohen]

From: Philip Herron <herron.phi...@googlemail.com>

Not adding the test case here we emit more errors than rustc for the error
type node so its just noisy and dejagnu is being a pain.

Fixes Rust-GCC#3933

gcc/rust/ChangeLog:

        * backend/rust-compile-resolve-path.cc (ResolvePathRef::resolve): 
return error_mark_node

Signed-off-by: Philip Herron <herron.phi...@googlemail.com>
---
 gcc/rust/backend/rust-compile-resolve-path.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/rust/backend/rust-compile-resolve-path.cc 
b/gcc/rust/backend/rust-compile-resolve-path.cc
index a80484acf09..6d92c0cd102 100644
--- a/gcc/rust/backend/rust-compile-resolve-path.cc
+++ b/gcc/rust/backend/rust-compile-resolve-path.cc
@@ -214,7 +214,8 @@ ResolvePathRef::resolve (const HIR::PathIdentSegment 
&final_segment,
 {
   TyTy::BaseType *lookup = nullptr;
   bool ok = ctx->get_tyctx ()->lookup_type (mappings.get_hirid (), &lookup);
-  rust_assert (ok);
+  if (!ok)
+    return error_mark_node;
 
   // need to look up the reference for this identifier
 
-- 
2.49.0