Minimize visibilities.

This makes it much clearer which things are used outside the crate.

compiler/rustc_codegen_ssa/src/common.rs

@@ -118,7 +118,7 @@ mod temp_stable_hash_impls {
     }
 }
 
-pub fn build_langcall<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
+pub(crate) fn build_langcall<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     bx: &Bx,
     span: Option<Span>,
     li: LangItem,
@@ -129,7 +129,7 @@ pub fn build_langcall<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     (bx.fn_abi_of_instance(instance, ty::List::empty()), bx.get_fn_addr(instance), instance)
 }
 
-pub fn shift_mask_val<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
+pub(crate) fn shift_mask_val<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>>(
     bx: &mut Bx,
     llty: Bx::Type,
     mask_llty: Bx::Type,