Follow-up commit d180086e6eae by fixing the left shift of signed integer entities through the use of a helper function. Specific per file changes are: * lib/msun/src/e_fmodf.c: * lib/msun/src/s_remquof.c: . Eliminate now unused variable 'i'. . Sort declaration statement. . Use subnormal_ilogbf() to avoid left shift of signed integer. * lib/msun/src/math_private.h b/lib/msun/src/math_private.h: . Implement subnormal_ilogbf() to extract an exponent of a subnormal float. This avoids left shifts of signed integers. . Update nearby comment. * lib/msun/src/s_ilogbf.c . Fix declaration of the function statement in accordance with style(9). . Use subnormal_ilogbf() to avoid left shift of signed integer. PR: 288850 MFC after: 1 week (cherry picked from commit c58c77246f88da87f309e8c449e98195d43e2c76)