[compiler-rt] [AArch64][compiler-rt] Add memcpy, memset, memmove, memchr builtins. (PR #77496)

[Jeremy Morse via llvm-commits]

jmorse wrote:

NB, I've taken a shot at fixing this with 5176df55d3 , I think using pythonize_bool is adding "_PYBOOL" to the end of the variable name that gets defined, like the nearby config flags (COMPILER_RT_TEST_STANDALONE_BUILD_LIBS for example gets _PYBOOL on the end).

https://github.com/llvm/llvm-project/pull/77496