gccrs: lang-items: Add Result and Try lang items

gcc/rust/ChangeLog:

	* util/rust-lang-item.h: Add handling for Result::Ok, Result::Err, Try, Try::into_result,
	Try::from_ok, Try::from_err.
	* util/rust-lang-item.cc: Likewise.

gcc/testsuite/ChangeLog:

	* rust/compile/try-trait.rs: New test.

2 files changed, 20 insertions, 0 deletions

diff --git a/gcc/rust/util/rust-lang-item.cc b/gcc/rust/util/rust-lang-item.cc
index 7460df0..ac90f97 100644
--- a/gcc/rust/util/rust-lang-item.cc
+++ b/gcc/rust/util/rust-lang-item.cc
@@ -97,11 +97,19 @@ const BiMap<std::string, LangItem::Kind> Rust::LangItem::lang_items = {{
   {"Some", Kind::OPTION_SOME},
   {"None", Kind::OPTION_NONE},
 
+  {"Ok", Kind::RESULT_OK},
+  {"Err", Kind::RESULT_ERR},
+
   {"into_iter", Kind::INTOITER_INTOITER},
   {"next", Kind::ITERATOR_NEXT},
 
   {"eq", Kind::EQ},
   {"partial_ord", Kind::PARTIAL_ORD},
+
+  {"try", Kind::TRY},
+  {"into_result", Kind::TRY_INTO_RESULT},
+  {"from_error", Kind::TRY_FROM_ERROR},
+  {"from_ok", Kind::TRY_FROM_OK},
 }};
 
 tl::optional<LangItem::Kind>
diff --git a/gcc/rust/util/rust-lang-item.h b/gcc/rust/util/rust-lang-item.h
index e68f055..ad081a7 100644
--- a/gcc/rust/util/rust-lang-item.h
+++ b/gcc/rust/util/rust-lang-item.h
@@ -127,8 +127,20 @@ public:
     OPTION_SOME,
     OPTION_NONE,
 
+    RESULT_OK,
+    RESULT_ERR,
+
     INTOITER_INTOITER,
     ITERATOR_NEXT,
+
+    // NOTE: These lang items are *not* necessarily present in later versions of
+    // Rust (I am unsure at which point they have been removed as the `Try`
+    // trait is unstable). They will need to be changed when updating the
+    // targeted Rust version of gccrs
+    TRY,
+    TRY_INTO_RESULT,
+    TRY_FROM_ERROR,
+    TRY_FROM_OK,
   };
 
   static const BiMap<std::string, Kind> lang_items;