New `--enforceReadonly` compiler option to enforce read-only semantics in type relations by ahejlsberg · Pull Request #58296 · microsoft/TypeScript

@ahejlsberg

# Conflicts:
#	src/compiler/diagnosticMessages.json
#	tests/baselines/reference/es2018IntlAPIs.types
#	tests/baselines/reference/es2020IntlAPIs.types
#	tests/baselines/reference/inferenceOptionalPropertiesToIndexSignatures.types
#	tests/baselines/reference/instantiationExpressions.types
#	tests/baselines/reference/localesObjectArgument.types
#	tests/baselines/reference/mappedTypeConstraints2.types
#	tests/baselines/reference/mappedTypeRecursiveInference.types
#	tests/baselines/reference/unionTypeInference.types
#	tests/baselines/reference/useObjectValuesAndEntries1.types
#	tests/baselines/reference/useObjectValuesAndEntries4.types