Enum class objects values and valueOf functions have kind SYNTHESIZED
Prettify code
Minor: fix typo
Fix an exception that can be thrown if quickfix still exists but psi is no longer valid
Minor: add @NotNull annotations
Use DescriptorToDeclarationUtil to get function declaration in JetChangeSignature
Check that target functions can be modified in JetChangeSignature
Add(Remove)ParameterQuickFix is not available for unmodifiable files