[ASan] Delete asan/dynamic dir and temporarily move the interposers...

[ASan] Delete asan/dynamic dir and temporarily move the interposers declarations to asan_intercepted_functions.h
Now that we have only one dependency on asan_intercepted_functions.h, we can unite that code with the interceptors declarations in asan_interceptors.cc and get rid of asan_intercepted_functions.h

llvm-svn: 175631