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_codegen_llvm/src/llvm/ffi.rs

@@ -2225,6 +2225,7 @@ unsafe extern "C" {
         IsLinkerPluginLTO: bool,
         NoPrepopulatePasses: bool,
         VerifyIR: bool,
+        LintIR: bool,
         UseThinLTOBuffers: bool,
         MergeFunctions: bool,
         UnrollLoops: bool,