Many of the files have using std::<foo> statements in them, but then the
use of <foo> will be inconsistently std::<foo> or <foo> scattered
through the file. This CL removes all of the using statements and
updates the code to have the required std:: prefix.
The limit for the number of struct members is parameterized using
command line options.
Add --max-struct-depth command line option.
Add --max-switch-branches command line option.
Add --max-function-args command line option.
Add --max-control-flow-nesting-depth option.
Add --max-access-chain-indexes option.
We are adding a new API which can be called to run the SPIR-V validator,
and retrieve the ValidationState_t object. This is very useful for
unit testing.
I have also added basic unit tests that demonstrate usage of this flow
and ease of use to verify correctness.
