gccrs: Add missing Sized, Copy and Clone lang item mappings

We need these lang items to be defined and later down the line the mappings
will be used to implement proper copy and clone logic.

Fixes #1786

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

gcc/rust/ChangeLog:

	* util/rust-lang-item.h:

gcc/testsuite/ChangeLog:

	* rust/compile/issue-1786.rs: New test.

2 files changed, 47 insertions, 0 deletions

diff --git a/gcc/rust/util/rust-lang-item.h b/gcc/rust/util/rust-lang-item.h
index 29c364b..c5ef620 100644
--- a/gcc/rust/util/rust-lang-item.h
+++ b/gcc/rust/util/rust-lang-item.h
@@ -80,6 +80,12 @@ public:
     FN_ONCE,
     FN_ONCE_OUTPUT,
 
+    // markers
+    COPY,
+    CLONE,
+    SIZED,
+
+    // delimiter
     UNKNOWN,
   };
 
@@ -237,6 +243,18 @@ public:
       {
 	return ItemType::FN_ONCE_OUTPUT;
       }
+    else if (item.compare ("copy") == 0)
+      {
+	return ItemType::COPY;
+      }
+    else if (item.compare ("clone") == 0)
+      {
+	return ItemType::CLONE;
+      }
+    else if (item.compare ("sized") == 0)
+      {
+	return ItemType::SIZED;
+      }
 
     return ItemType::UNKNOWN;
   }
@@ -321,6 +339,12 @@ public:
 	return "fn_once";
       case FN_ONCE_OUTPUT:
 	return "fn_once_output";
+      case COPY:
+	return "copy";
+      case CLONE:
+	return "clone";
+      case SIZED:
+	return "sized";
 
       case UNKNOWN:
 	return "<UNKNOWN>";
diff --git a/gcc/testsuite/rust/compile/issue-1786.rs b/gcc/testsuite/rust/compile/issue-1786.rs
new file mode 100644
index 0000000..f73b63d
--- /dev/null
+++ b/gcc/testsuite/rust/compile/issue-1786.rs
@@ -0,0 +1,23 @@
+#[lang = "clone"]
+trait Clone {
+    fn clone(&self) -> Self;
+
+    fn clone_from(&mut self, source: &Self) {
+        *self = source.clone()
+    }
+}
+
+#[lang = "copy"]
+pub trait Copy: Clone {
+    // Empty.
+}
+
+mod impls {
+    use super::Clone;
+
+    impl Clone for char {
+        fn clone(&self) -> Self {
+            *self
+        }
+    }
+}