Fix the test to disassemble as if at address zero, not at an invalid address....

Fix the test to disassemble as if at address zero, not at an invalid address. The default SBAddress constructor sets the offset to 0xffffffffffffffff and the section to NULL.

This was causing problems on clang 602 branches that use MemoryObjects to as the container for opcode bytes instead of a plain array of bytes. So we were asking for 3 bytes to be disassembled at address 0xffffffffffffffff which would cause an unsigned overflow and cause the MemoryObject to refuse to read anymore bytes.

llvm-svn: 227153