bitbake: codeparser: don't interact with the cache for subshells

bitbake: codeparser: don't interact with the cache for subshells

Doing so was causing leakage between the execs of the main value and that of
the subshell value, and was causing the cached subshell value to be used for
the overall variable. At the least this could cause execs contamination
between two variables that while differing, run the same subshell. Beyond
that, it's possible we could have been using an incomplete cached value of
a subshell for that of the main value.

Before this, bb_codeparser.dat would change between parses with differing
bbfile parse order. After, it does not change.

The codeparser cache version is bumped, to ensure we don't use potentially
incorrect cached values from previous runs.

This should hopefully resolve the difficult-to-reproduce issues we've seen at
Mentor Graphics where bitbake emits a script to run a task and misses
dependent functions, resulting in 'command not found' failures. This issue has
also been mentioned on the oe devel list, where someone hit a case where
oe_runmake was missing from a do_install task (IIRC). Adding debug information
showed that bitbake's information about the variable dependencies for this
task is inaccurate in the failure cases.

(Bitbake rev: 97537e4786a1e3a329249497498b59b8f5174fc3)

Signed-off-by: Christopher Larson <kergoth@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>