This is 2nd trial of I30a0914a4633bd93eb60957cdf378770f04d8428

- To suppress noisy unused parameter warnings, comment out unused
  arguments.
- Add -Werror for suppressing further warning.
- Add -Wall -Wextra for safety.
- Use "z" prefix for format string of size_t.

Verified that compile succeeded on all arm,arm64,mips,x86,x86_64.

Change-Id: I7ad208464486b8a35da53929cb1cfe541ed0052f