Auto merge of #134864 - Zalathar:rollup-suc8ay9, r=Zalathar

Rollup of 3 pull requests

Successful merges:

 - #134849 (compiletest: Slightly simplify the handling of debugger directive prefixes)
 - #134850 (Document virality of `feature(rustc_private)`)
 - #134852 (Added a codegen test for optimization with const arrays)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 15 insertions, 0 deletions

diff --git a/tests/codegen/const-array.rs b/tests/codegen/const-array.rs
new file mode 100644
index 00000000000..f2b331c315d
--- /dev/null
+++ b/tests/codegen/const-array.rs
@@ -0,0 +1,15 @@
+//@ compile-flags: -O
+
+#![crate_type = "lib"]
+
+const LUT: [u8; 2] = [1, 1];
+
+// CHECK-LABEL: @decode
+#[no_mangle]
+pub fn decode(i: u8) -> u8 {
+    // CHECK: start:
+    // CHECK-NEXT: icmp
+    // CHECK-NEXT: select
+    // CHECK-NEXT: ret
+    if i < 2 { LUT[i as usize] } else { 2 }
+}