Rollup merge of rust-lang#82799 - bugadani:codegen-tests, r=nagisa

Add regression test for rust-lang#75525

Author: m-ou-se

src/test/codegen/issue-75525-bounds-checks.rs

@@ -0,0 +1,27 @@
+// Regression test for #75525, verifies that no bounds checks are generated.
+
+// min-llvm-version: 12.0.0
+// compile-flags: -O
+
+#![crate_type = "lib"]
+
+// CHECK-LABEL: @f0
+// CHECK-NOT: panic
+#[no_mangle]
+pub fn f0(idx: usize, buf: &[u8; 10]) -> u8 {
+    if idx < 8 { buf[idx + 1] } else { 0 }
+}
+
+// CHECK-LABEL: @f1
+// CHECK-NOT: panic
+#[no_mangle]
+pub fn f1(idx: usize, buf: &[u8; 10]) -> u8 {
+    if idx > 5 && idx < 8 { buf[idx - 1] } else { 0 }
+}
+
+// CHECK-LABEL: @f2
+// CHECK-NOT: panic
+#[no_mangle]
+pub fn f2(idx: usize, buf: &[u8; 10]) -> u8 {
+    if idx > 5 && idx < 8 { buf[idx] } else { 0 }
+}