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

(cherry picked from commit e93be99da0)

Change-Id: I347792dab25c7b19c3fc690e03d20899ce1e26e0

linker/linker_phdr.h

@@ -101,6 +101,7 @@ int phdr_table_get_arm_exidx(const ElfW(Phdr)* phdr_table, size_t phdr_count, El
 #endif
 
 void phdr_table_get_dynamic_section(const ElfW(Phdr)* phdr_table, size_t phdr_count,
-                                    ElfW(Addr) load_bias, ElfW(Dyn)** dynamic);
+                                    ElfW(Addr) load_bias, ElfW(Dyn)** dynamic,
+                                    ElfW(Word)* dynamic_flags);
 
 #endif /* LINKER_PHDR_H */