[COMMITTED] gccrs: add testcase to test component_ref and constructor codes in eval_constant_expression()

[Arthur Cohen]

From: Faisal Abbas <90.abbasfai...@gmail.com>

gcc/testsuite/ChangeLog:

        * rust/compile/const7.rs: New test.

Signed-off-by: Faisal Abbas <90.abbasfai...@gmail.com>

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/testsuite/rust/compile/const7.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 gcc/testsuite/rust/compile/const7.rs

diff --git a/gcc/testsuite/rust/compile/const7.rs 
b/gcc/testsuite/rust/compile/const7.rs
new file mode 100644
index 00000000000..a7431c0c4d2
--- /dev/null
+++ b/gcc/testsuite/rust/compile/const7.rs
@@ -0,0 +1,12 @@
+// { dg-options "-w -O0 -fdump-tree-gimple" }
+struct Foo(usize, usize);
+
+const A:Foo = Foo(123, 4546);
+
+const B:usize = A.0;
+
+fn main() {
+    // { dg-final { scan-tree-dump-times {b = 123} 1 gimple } }
+    let b = B;
+}
+
-- 
2.39.1