Dump C/C++ vtable & record layout information (clang + msvc + gcc)

Dump CPP vtable & record layout information

# Requirements:
#   clang - The classes/structs you want to dump must be used in code at least once, not just defined.
#   MSVC  - The classes/structs you want to dump must have "MEOW" in the name for "reportSingleClass" to work.
# Usage:
#   $ make dump_vtables file=test.cpp
dump_vtables:
  clang -cc1 -fdump-record-layouts -emit-llvm  $(file) > clang-vtable-layout-$(file).txt
  clang -cc1 -fdump-vtable-layouts -emit-llvm  $(file) > clang-record-layout-$(file).txt
  g++ -fdump-lang-class=$(file).txt $(file)
  cl.exe $(file) /d1reportSingleClassLayoutMEOW > msvc-single-class-vtable-layout-$(file).txt
  cl.exe $(file) /d1reportAllClassLayout > msvc-all-class-vtable-layout-$(file).txt