Currently ExecutionEngine tries to dump all functions declared in the
module, even those which are "external" (i.e., linked/loaded at
runtime). E.g.
```mlir
func.func private @printF32(f32)
func.func @supported_arg_types(%arg0: i32, %arg1: f32) {
call @printF32(%arg1) : (f32) -> ()
return
}
```
fails with
```
Could not compile printF32:
Symbols not found: [ __mlir_printF32 ]
Program aborted due to an unhandled Error:
Symbols not found: [ __mlir_printF32 ]
```
even though `printF32` can be provided at final build time (i.e., when
the object file is linked to some executable or shlib). E.g, if our own
`libmlir_c_runner_utils` is linked.
So just skip functions which have no bodies during dump (i.e., are decls
without defns).
cd9d48777e