Having different code paths for streamed and regular bitcode reading was a
source of bugs in the past and this defines them away.
It has a small but noticeable impact on performance. I timed running
"opt -disable-output -disable-verify" on a ltoed clang. It goes from
14.752845231 seconds time elapsed ( +- 0.16% )
to
15.012463721 seconds time elapsed ( +- 0.11% )
Extracted from a patch by Karl Schimpf.
llvm-svn: 240305