go: Update reproducibility patch to fix panic errors

Based on a discussion on the mailing list [1], there are panic
errors that occur on a few platforms caused by the patch.  We
cannot simply remove the original patch due to the
reproducibility issues that it addresses, so this patch on the
original patch fixes the cause of the panic errors.

The previous version of this patch was a little too aggressive
in cleaning up the environment.  Some of the variables impacted
by the filerCompilerFlags() function require at least one value
to remain in the array.  In this case, the values for ccExe,
cxxExe, and fcExe require a value or later code that access
them result in a panic related to accessing a value out of range.

This updated patch adds a flag that requires keeping the first
value so that at least one thing remains and the assignments
for the Exes set that flag to true.  The first item in the
array should be the executable name, so leaving it should be
safe.

I have run the oe-selftest and everything passed in my setup.

There is a bug report [2] filed for the issue that this patch
addresses.

[YOCTO #14976]

[1] https://lists.openembedded.org/g/openembedded-core/topic/94022663
[2] https://bugzilla.yoctoproject.org/show_bug.cgi?id=14976



Signed-off-by: Ryan Eatmon <reatmon@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
(cherry picked from commit 9eaa3a81)
Signed-off-by: Steve Sakoman <steve@sakoman.com>