a5ddd92035
This change added support of calling async execute inside async.func.
Ex.
```
async.func @async_func_call_func() -> !async.token {
%token = async.execute {
%c0 = arith.constant 0 : index
memref.store %arg0, %arg1[%c0] : memref<1xf32>
async.yield
}
async.await %token : !async.token
return
}
```
Reviewed By: ezhulenev
Differential Revision: https://reviews.llvm.org/D141730