Auto merge of rust-lang#142259 - sayantn:simplify-intrinsics, r=workingjubilee

Simplify implementation of Rust intrinsics by using type parameters in the cache

The current implementation of intrinsics have a lot of duplication to handle different overloads of overloaded LLVM intrinsic. This PR uses the **base name and the type parameters** in the cache instead of the full, overloaded name. This has the benefit that `call_intrinsic` doesn't need to provide the full name, rather the type parameters (which is most of the time more available). This uses `LLVMIntrinsicCopyOverloadedName2` to get the overloaded name from the base name and the type parameters, and only uses it to declare the function.

(originally was part of rust-lang#140763, split off later)

`@rustbot` label A-codegen A-LLVM
r? codegen

Author: bors

src/builder.rs

@@ -897,7 +897,7 @@ impl<'a, 'gcc, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'gcc, 'tcx> {
     fn checked_binop(
         &mut self,
         oop: OverflowOp,
-        typ: Ty<'_>,
+        typ: Ty<'tcx>,
         lhs: Self::Value,
         rhs: Self::Value,
     ) -> (Self::Value, Self::Value) {