Appease ASAN in Mesa 9.0.3

In _mesa_add_parameter, in prog_parameter.c, |values| represents an
array holding a variable number of values. These values get copied out
of the array 4 at a time with the COPY_4V macro, however, the array
might only contain a single element. In this case, ASAN reports a
read-before-initialize because the last 3 of the 4 elements haven't
been written to yet.

This patch should be upstreamed to Mesa.

BUG=238755
NOTRY=true

[Ken Russell (switch to Gerrit), 2013-06-17 19:30:22]

Note that this patch should probably be upstreamed to Mesa.

I'll try to modify the description to indicate this, and commit this patch via
the commit queue.

[commit-bot: I haz the power, 2013-06-17 19:31:27]

No LGTM from a valid reviewer yet. Only full committers are accepted.
Even if an LGTM may have been provided, it was from a non-committer or
a lowly provisional committer, _not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[Ken Russell (switch to Gerrit), 2013-06-17 19:32:28]

Oops. LGTM

[commit-bot: I haz the power, 2013-06-17 19:32:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mymax@amazon.com/17122007/13001

[commit-bot: I haz the power, 2013-06-17 19:33:05]

Change committed as 206770