Remove some unused / noop emit flags

[jakebailey]

These flags are either unused, or do nothing due to us dropping ES5 or restructuring faked imports.

[Copilot]

Pull request overview

Removes emit flags that are unused or have become no-ops in this TypeScript compiler/LS Go port, simplifying emit/transform logic and reducing dead code paths.

Changes:

• Removed EFNeverApplyImportHelper and deleted now-dead conditional logic in the CommonJS module transformer.
• Removed EFInternalName and EFNoHoisting emit flags and cleaned up remaining call sites/comments.
• Simplified external helpers import emit-flagging to only apply EFCustomPrologue.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
internal/transformers/moduletransforms/externalmoduleinfo.go	Stops applying removed EFNeverApplyImportHelper to synthetic external-helpers imports.
internal/transformers/moduletransforms/commonjsmodule.go	Deletes dead branches that checked EFNeverApplyImportHelper and simplifies default-export handling.
internal/transformers/estransforms/using.go	Removes masking of the deleted EFInternalName flag when cloning identifiers.
internal/transformers/estransforms/forawait.go	Removes application of the deleted EFNoHoisting flag.
internal/printer/emitflags.go	Removes the unused/no-op emit flags from the canonical definition list.
internal/compiler/fileloader.go	Deletes stale commented-out code referencing removed internal emit-flag behavior.
internal/checker/nodebuilderimpl.go	Marks synthesized property-access expressions with EFNoIndentation.