Xtensa: Revise xtensa_expand_prologue()
This commit refactors ``xtensa_expand_prologue()`` to use C++ references instead of pointers for return values.
This commit refactors the xtensa_expand_prologue() function in the Xtensa backend. It changes the arguments of xtensa_can_eliminate_callee_saved_reg_p to use C++ references instead of pointers for returning values, as well as adjusting the call to xtensa_can_eliminate_callee_saved_reg_p() in xtensa_expand_prologue to match the changes. There are no functional changes.
In Details
The xtensa_expand_prologue() function is responsible for generating the function prologue code for the Xtensa architecture. This commit refactors the code to use C++ references instead of pointers. Search terms: GCC Xtensa xtensa_expand_prologue.
For Context
A function prologue is a sequence of instructions at the beginning of a function that sets up the stack frame and saves registers. This commit modifies the code generation for function prologues on the Xtensa architecture, using C++ references instead of pointers for return values. This is a refactoring change that does not affect the functionality of the code. Search terms: GCC Xtensa xtensa_expand_prologue.