Fix gdb could not get shared library list issue

Get dynamic flags from phdr table's correct entry rather the first
entry, so that the following DT_DEBUG entry can be set.

Also fix the undefined reference to LoadTask::deleter issue under gcc
-O0 option.

Bug: 17524778
Change-Id: I9c679af197b034761fb739d6c980e628ff2ab84c
3 files changed