Scope validation performance boost

[TwitchBronBron]

Several fixes:

• leverage child-parent linking introduced in Link children to their parents in AST #650 to speed up scope validation
• optimize scope validation by eliminating duplicate file checks when possible

While this hasn't restored the original performance lost in 0.53.0, it's a step in the right direction.

Breaking changes:

• removed NamespaceStatement.symbolTable in favor of NamespaceStatement.getSymbolTable() because the symbol table for namespaces actually reside within the NamespaceStatement.body property. Since the symbolTable logic was only recently added, it's unlikely that many projects are referencing it.

• removed the namespaceName from several AstNodes, in favor of external consumers needing to call .findAncestor(isNamespaceStatement) instead. Note, this relies heavily on the AstNode.parent property which is set at the start of onFileValidate for each file. This is breaking because previously, the .namespaceName property was available immediately in afterFileParse. However, that logic was unsustainable for plugins that manipulate AST, and it's unlikely that many plugins are leveraging that property, so it is worth the breaking change.

  Here are the nodes with the removed property:

  • VariableExpression
  • DottedGetExpression
  • CallExpression
  • FunctionStatement

[TwitchBronBron]

Some of the fixes have further improved performance. Still not as good as 0.52.3, but better than when this PR was originally submitted.

[TwitchBronBron]

This was moved into the EnumStatement callback above.

[TwitchBronBron]

Symbol table linking/unlinking happens at the program event level, we don't need to do it here anymore.

[TwitchBronBron]

This is the core of the performance improvement. The expression info is computed once for each file (previously this would happen once per scope per file).