Add ppc64le linux hardwire for ld64.so.2 strcmp

Add ppc64le linux hardwire for ld64.so.2 strcmp

When dlopen is used we might end up in an assembly powerpc/strcmp.S
variant that is optimized in a way memcheck cannot proof correct. We
try to intercept strcmp in ld.so, but might fail when strcmp is called
before our interception code is loaded. Having an hardwire for ld.so
strcmp (earlier intercept) would solve this.

https://bugs.kde.org/show_bug.cgi?id=508145

(cherry picked from commit 78fe3625f6b8ed4de28527d71c4a98d70e5b3035)