Makes some white-space differences in most output, plus a few cases
where more could have been put out but was cut short by the previous
fix-sized buffer.
This needs some render testing, but is destined to be part of master.
This also leads to a variety of other simplifications.
- IO are global symbols, so only need one list of linkage nodes (deferred)
- no longer need parse-context-wide 'inEntryPoint' state, entry-point is localized
- several parts of splitting/flattening are now localized
Since EOpMatrixSwizzle is a new op, existing back-ends only work when the
front end first decomposes it to other operations. So far, this is only
being done for simple assignment into matrix swizzles.
This partially addressess issue #670, for when the matrix swizzle
degenerates to a component or column: m[c], m[c][r] (where HLSL
swaps rows and columns for user's view).
An error message is given for the arbitrary cases not covered.
These cases will work for arbitrary use of l-values.
Future work will handle more arbitrary swizzles, which might
not work as arbitrary l-values.
