The two functions PyOS_strnicmp() and PyOS_stricmp() from Python/pystrcmp.c are no longer used by any function in the core. Because no module references any object from Python/pystrcmp.c the object file is not included in the Python binary:

$ nm -P python | grep ^PyOS | sort
PyOS_AfterFork T 000000000044040e 0000000000000036
PyOS_double_to_string T 00000000005da3de 0000000000000119
PyOS_FiniInterrupts T 0000000000440380 000000000000000b
PyOS_getsig T 0000000000423994 0000000000000041
PyOS_InitInterrupts T 00000000004402f5 000000000000008b
PyOS_InputHook B 000000000095d478 0000000000000008
PyOS_InterruptOccurred T 000000000044038b 000000000000003e
PyOS_ReadlineFunctionPointer B 000000000095d5c8 0000000000000008
PyOS_Readline T 000000000063ffb5 000000000000012e
PyOS_setsig T 00000000004239d5 0000000000000078
PyOS_snprintf T 000000000041c7bc 00000000000000b8
PyOS_StdioReadline T 000000000063fe1c 0000000000000199
PyOS_string_to_double T 00000000005d9b50 0000000000000146
PyOS_strtol T 00000000005d3ded 00000000000000d6
PyOS_strtoul T 00000000005d3a00 00000000000003ed
PyOS_vsnprintf T 000000000041c874 00000000000000c4

Neither Python 2.7 nor 3.3+ include the functions in their binaries. 2.6 and 3.2 are not affected. The functions are part of the documented and stable API but apparently they are not used very often.