MFC r326136: bfd: avoid crash on corrupt binaries

From binutils commits 5a4b0ccc20ba30caef53b01bee2c0aaa5b855339 and
7e1e19887abd24aeb15066b141cdff5541e0ec8e, made available under GPLv2
by Nick Clifton.

PR: 198824
Security: CVE-2014-8501
Security: CVE-2014-8502