gccrs: tychk: Add more support for additional trait bounds in functions

This commit correctly lowers and typechecks parenthesized types, which are used for trait objects with additional bounds.

gcc/rust/ChangeLog:

	* resolve/rust-ast-resolve-type.cc (ResolveType::visit): New visitor to handle
	ParenthesizedType.
	* resolve/rust-ast-resolve-type.h: Likewise.
	* typecheck/rust-hir-type-check-type.cc (TypeCheckType::visit): Likewise.
	* typecheck/rust-hir-type-check-type.h: Likewise.

gcc/testsuite/ChangeLog:

	* rust/compile/auto_traits2.rs: New test.
	* rust/compile/auto_traits3.rs: New test.
	* rust/compile/nr2/exclude: Add auto_traits2 test.

3 files changed, 62 insertions, 0 deletions

diff --git a/gcc/testsuite/rust/compile/auto_traits2.rs b/gcc/testsuite/rust/compile/auto_traits2.rs
new file mode 100644
index 0000000..7d0dcc1
--- /dev/null
+++ b/gcc/testsuite/rust/compile/auto_traits2.rs
@@ -0,0 +1,26 @@
+#![feature(optin_builtin_traits)]
+
+pub unsafe auto trait Send {}
+#[lang = "sync"]
+pub unsafe auto trait Sync {}
+
+trait A {
+    fn a_method(&self) {}
+}
+
+fn foo(a: &(dyn A + Send + Sync)) {
+    a.a_method();
+}
+
+struct S;
+
+impl A for S {
+    fn a_method(&self) {}
+}
+
+fn main() {
+    let s = S;
+
+    foo(&s); // { dg-error "bounds not satisfied" }
+             // { dg-error "mismatched type" "" { target *-*-* } .-1 }
+}
diff --git a/gcc/testsuite/rust/compile/auto_traits3.rs b/gcc/testsuite/rust/compile/auto_traits3.rs
new file mode 100644
index 0000000..81c39ec
--- /dev/null
+++ b/gcc/testsuite/rust/compile/auto_traits3.rs
@@ -0,0 +1,34 @@
+#![feature(optin_builtin_traits)]
+
+pub unsafe auto trait Send {}
+#[lang = "sync"]
+pub unsafe auto trait Sync {}
+
+trait A {
+    fn a_method(&self) {}
+}
+
+fn foo(a: &(dyn A + Send + Sync)) {
+    a.a_method();
+}
+
+struct S;
+
+impl A for S {
+    fn a_method(&self) {} // { dg-warning "unused" }
+}
+
+// These should not be necessary because they are both auto traits
+// They need to be removed once we figure out the proper implementation for each of them
+// However, it'd be silly to implement other traits in order to ensure the test is okay,
+// as these extra trait bounds are only allowed to use auto traits
+// FIXME: #3327
+// FIXME: #3326
+unsafe impl Send for S {}
+unsafe impl Sync for S {}
+
+fn main() {
+    let s = S;
+
+    foo(&s);
+}
diff --git a/gcc/testsuite/rust/compile/nr2/exclude b/gcc/testsuite/rust/compile/nr2/exclude
index 2a5bc94..e23669f3 100644
--- a/gcc/testsuite/rust/compile/nr2/exclude
+++ b/gcc/testsuite/rust/compile/nr2/exclude
@@ -207,4 +207,6 @@ issue-2907.rs
 issue-2423.rs
 issue-266.rs
 additional-trait-bounds2.rs
+auto_traits2.rs
+auto_traits3.rs
 # please don't delete the trailing newline