message: Add _GLIBCXX_SANITIZE_VECTOR on debug builds
  > When defined, std::vector operations will be annotated so that
  AddressSanitizer can detect invalid accesses to the unused capacity of a
  std::vector.
diff: @@ -104,7 +104,7 @@ endif
  ifeq ($(CFG), debug)
  ODIR=_debug
  CFLAGS += -O0 -DDEBUG
  - CFLAGS += -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC
  + CFLAGS += -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC -D_GLIBCXX_SANITIZE_VECTOR
  else
  ODIR=_release
  CFLAGS += -O2 -DNDEBUG
  