error: argument 1 is required to be a constant
  --> $DIR/rustc-args-required-const.rs:34:5
   |
LL |     foo(a); //~ ERROR: argument 1 is required to be a constant
   |     ^^^^^^

error: argument 2 is required to be a constant
  --> $DIR/rustc-args-required-const.rs:36:5
   |
LL |     bar(a, a); //~ ERROR: argument 2 is required to be a constant
   |     ^^^^^^^^^

error: aborting due to 2 previous errors