Refresh darwin-x86/arm-linux-androideabi-gdb to 7.6

This prebuilt is built against AOSP-toolchain/gdb/gdb-7.6
commit 1c4be8e861df1416efe1812dfe0c6e7a096d9d60

Change-Id: Ib3a16f083d8d06349f95c92685681bdb96ad1cf4
22 files changed