feat(tvix/eval): implement upvalue resolution in with scopes

These need to be handled specially by the runtime if the compiler
determines that a given local must be resolved via `with`.

Note that this implementation has a bug: It currently allows `with`
inside of nested lambdas to shadow statically known identifiers. This
will be cleaned up in the next commit.

Change-Id: If196b99cbd1a0f2dbb4a40a0e88cdb09a009c6b9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6299
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

tvix/eval/src/opcode.rs

@@ -115,4 +115,5 @@ pub enum OpCode {
     // according to the count.
     DataLocalIdx(StackIdx),
     DataUpvalueIdx(UpvalueIdx),
+    DataDynamicIdx(ConstantIdx),
 }