gccrs: fix ICE when closure body is not a block

Fixes: #2052

gcc/rust/ChangeLog:

	* backend/rust-compile-expr.cc (CompileExpr::generate_closure_function):
	when its not a block we dont have any ribs to generate locals from

gcc/testsuite/ChangeLog:

	* rust/execute/torture/issue-2052.rs: New test.

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

1 files changed, 15 insertions, 0 deletions

diff --git a/gcc/testsuite/rust/execute/torture/issue-2052.rs b/gcc/testsuite/rust/execute/torture/issue-2052.rs
new file mode 100644
index 0000000..6c15eb3
--- /dev/null
+++ b/gcc/testsuite/rust/execute/torture/issue-2052.rs
@@ -0,0 +1,15 @@
+#[lang = "fn_once"]
+pub trait FnOnce<Args> {
+    #[lang = "fn_once_output"]
+    type Output;
+
+    extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
+}
+
+pub fn f() -> i32 {
+    (|| 42)()
+}
+
+pub fn main() -> i32 {
+    f() - 42
+}