[clang-tools-extra] [clang-tidy][readability] Ignore macros in function-size check (PR #199549)

[via cfe-commits]

savchart wrote:

One note about the `macro_wrap` case: the current check, `!Loc.isMacroID()`, treats all macro-expanded tokens the same.

Using `SM.isMacroArgExpansion(Loc)` would let us distinguish tokens coming from the macro definition body from tokens written by the user as macro arguments at the call site.

https://github.com/llvm/llvm-project/pull/199549