Introduce generateCodeForArgument() in CodeFlow #32708
Description
Overview
SpelNodeImpl currently defines a generateCodeForArgument() utility method which "asks an argument to generate its bytecode and then follow it up with any boxing/unboxing/checkcasting to ensure it matches the expected parameter descriptor."
This utility method is currently protected and cannot be used outside the org.springframework.expression.spel.ast; however, there are times when it would be beneficial to be able to invoke this method from types within the org.springframework.expression.spel package that deal with compilation.
This is a prerequisite for the forthcoming CompilableIndexAccessor.