We are hitting the warning in template code with bool and loop like this: "for (const auto& element : value)" where element is bool from template. But not always.
When it is bool the warning triggers:
error: loop variable 'element' is always a copy because the range of type 'const std::vector<bool, allocator<bool> >' does not return a reference [-Werror,-Wrange-loop-analysis]

Combined two if into one.

Ping @aaron.ballman , please verify the change.

Hi Aaron,

Removed check for libraries.

Manoj, please check updated diff.

Changed Wpoison-system-directories warning to be disabled by default.

Fixed clang-format.

Updated the code (removed Diag propagation).
Added test cases.

Taking ownership of the change as Yunlian is no longer working on this CL.