This patch adds another frame-format variable (currently only
implemented in the CPlusPlus language plugin) that represents the
"suffix" of a function. The name is derived from the `DotSuffix` node of
LLVM's Itanium demangler.
For a function name such as `int foo() (.cold)`, the suffix would be
`(.cold)`.
Adds the new `plugin.cplusplus.display.function-name-format` setting and makes the `${function.name-with-args}` query it for formatting the function name.
One caveat is that the setting can't itself be set to `${function.name-with-args}` because that would cause infinite recursion and blow the stack. I added an XFAILed test-case for it and will address it in a follow-up patch.
https://github.com/llvm/llvm-project/pull/131836