This PR strengthens below two cases:
1. Support calculate unsized array size for any type. Previously,
it reported error when the type was a structure.
2. Correctly add the right paren for store function when any
load/length functions are nested in it.

Bug: angleproject:5734
Change-Id: I3428fa35f1481275e1d193094ceddb011f747cf1
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2762655Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jiajia Qin <jiajia.qin@intel.com>