Symbol value transcription is not working

[nirosys]

After fixing multi-then evaluation, a new failure showed up. With some added output, we can see that the rendered document is not substituting the appropriate symbol ID given the DSL symbol ID notation.

Running tests: ./ion-tests/conformance/core/toplevel_produces.ion
Input: <<Ok("$ion_1_0  ")>>
Actual: None      Expected: None
Input: <<Ok("$ion_1_0 null a::null '#$1'::null  ")>>
Actual: Some(null)      Expected: Some(null)
Actual: Some(a::null)      Expected: Some(a::null)
Actual: Some('#$1'::null)      Expected: Some($ion::null)     <-- Here. 
  check interpretation of core AST-forms in toplevel and produces   ...  [Failed]

[nirosys]

Another instance (conformance/ivm.ion):

(toplevel '#$ion_12_34')

This is not transcribing the symbol, but writing the literal #$ion_12_34 as a symbol.

[nirosys]

Another issue where transcribed symbols aren't making it through correctly:

ConformanceError(ConformanceErrorImpl { file: "", test_name: "", kind: IonError(Encoding(EncodingError { description: "symbol value ID $10 is not in the symbol table" })) })

Having a symbol table defined (in this case in 1.0) and transcribing a known numeric symbol ID is failing, seemingly, because the creation of the symbol table import isn't being reflected in the encoding context when writing the raw symbol id.

(ion_1_0 "imports entry is ignored if name is empty or malformed"
  (each (toplevel $ion_symbol_table::{imports:[{name:""},          {name:"abcs"}]})
        (toplevel $ion_symbol_table::{imports:[{name:null},        {name:"abcs"}]})
        (toplevel $ion_symbol_table::{imports:[{name:null.string}, {name:"abcs"}]})
        (toplevel $ion_symbol_table::{imports:[{name:1, version:1},{name:"abcs"}]})
        (then (toplevel '#$10') // <-- Fails to write here.
              (produces a))))