[lldb] Don't send invalid region addresses to lldb server
Previously when <addr> in "memory region <addr>" didn't
parse correctly, we'd print an error then also ask lldb-server
for a region containing LLDB_INVALID_ADDRESS.
(lldb) memory region not_an_address
error: invalid address argument "not_an_address"...
error: Server returned invalid range
Only send the command to lldb-server if the address
parsed correctly.
(lldb) memory region not_an_address
error: invalid address argument "not_an_address"...
Reviewed By: labath
Differential Revision: https://reviews.llvm.org/D87694