[lldb] max_return_elements parameter not used in SBCommandInterpreter::HandleCompletionWithDescriptions

[eronnen]

SBCommandInterpreter::HandleCompletionWithDescriptions potentially can return more than max_return_elements completions, can cause a major slowdown when trying to complete a breakpoint statement for a program with a lot of symbols

[llvmbot]

@llvm/issue-subscribers-lldb

Author: Ely Ronnen (eronnen)

`SBCommandInterpreter::HandleCompletionWithDescriptions` potentially can return more than `max_return_elements` completions, can cause a major slowdown when trying to complete a breakpoint statement for a program with a lot of symbols