[sanitizer] More syscall handler placeholders.

This time it's the full list scavenged from syscalls.h
Fixed return value type.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@179378 91177308-0d34-0410-b5e6-96231b3b80d8
[sanitizer] Add syscall handlers to ASan and TSan runtimes.

ASan checks addressability of syscall arguments. TSan does nothing for now.


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@179380 91177308-0d34-0410-b5e6-96231b3b80d8