More specifically, we do a proper masked store (rather than a load-
blend-store) unless we can determine that we're accessing a stack-allocated
"varying" variable. This fixes a number of nefarious bugs where given
code like:
uniform float a[21];
foreach (i = 0 … 21)
a[i] = 0;
We'd use a blend and in turn read past the end of a[] in the last
iteration.
Also made slight changes to inlining in aobench; this keeps compiles
to ~5s, versus ~45s without them (with this change).
Fixes issue #160.