compiler: Lower fn call arg spans down to MIR

To enable improved accuracy of diagnostics in upcoming commits.

compiler/rustc_codegen_cranelift/src/intrinsics/llvm.rs

@@ -7,7 +7,7 @@ pub(crate) fn codegen_llvm_intrinsic_call<'tcx>(
     fx: &mut FunctionCx<'_, '_, 'tcx>,
     intrinsic: &str,
     generic_args: GenericArgsRef<'tcx>,
-    args: &[mir::Operand<'tcx>],
+    args: &[Spanned<mir::Operand<'tcx>>],
     ret: CPlace<'tcx>,
     target: Option<BasicBlock>,
     span: Span,