Provides isolation of mem{cpy,set,move} in the DR static library on AArchXX. Moves the assembly mem{cpy,set} into a separate memfuncs.asm for arm and aarch64, and links in memmove.c. Marks the __mem{cpy,set}_chk aliases as weak. This brings AArchXX into parity with x86 on library symbol isolation.
Removes the exceptions for AArchXX in the CMake_symbol_check test. Confirms the build-time test fails without the code changes here:
CMake Error at xxx/core/CMake_symbol_check.cmake:98 (message): *** Error: xxx/build_a64_dbg_tests/lib64/debug/libdynamorio_static_nohide.a contains a likely-to-conflict symbol: 4279: 00000000002cea3c 0 FUNC GLOBAL HIDDEN 248 memcpy
Issue: #3315 (closed), #3348