elf: Use d_ptr instead of d_val when reading from a dynamic array
elf: Use d_ptr instead of d_val when reading from a dynamic array

The dynamic array reader should treat data as unsigned when initially
reading values from the array to prevent premature sign-extension. The
glibc and traditional android headers define d_val using Elf32_Word, an
unsigned type. linux/elf.h, used by unified android headers, defines
d_val using Elf32_Sword, a signed type. Use d_ptr instead since it's
always an unsigned type.

Bug: crashpad:30
Change-Id: Ie8e88941fefc7075621aefe226fdba33b1f6129c
Reviewed-on: https://chromium-review.googlesource.com/847818
Commit-Queue: Joshua Peraza <f5809a5e35ec7e1bd0e25cb0a0b68bb433cf6f17@chromium.org>
Reviewed-by: Mark Mentovai <f1b5a91d4d6ad523f2610114591c007e75d15084@chromium.org>

chromium/crashpad,chromium/crashpad,chromium/crashpad