Rollup merge of #128970 - DianQK:lint-llvm-ir, r=nikic

Add `-Zlint-llvm-ir`

This flag is similar to `-Zverify-llvm-ir` and allows us to lint the generated IR.

r? compiler

compiler/rustc_interface/src/tests.rs

@@ -795,6 +795,7 @@ fn test_unstable_options_tracking_hash() {
     tracked!(instrument_xray, Some(InstrumentXRay::default()));
     tracked!(link_directives, false);
     tracked!(link_only, true);
+    tracked!(lint_llvm_ir, true);
     tracked!(llvm_module_flag, vec![("bar".to_string(), 123, "max".to_string())]);
     tracked!(llvm_plugins, vec![String::from("plugin_name")]);
     tracked!(location_detail, LocationDetail { file: true, line: false, column: false });