According to Section 2.17 (Universal Limits) of the SPIR-V Spec, the
control flow nesting depth may not be larger than 1023.
This is checked only when we are required to have structured
control flow. Otherwise it's not clear how to compute control
flow nesting depth.
According to sectin 2.17 in SPIR-V Spec, the structure nesting depth may
not be larger than 255. This is interpreted as structures nested in
structures. The code does not look into arrays or follow pointers to see
if it reaches a structure downstream.
Use memoization to avoid exponential runtime.
According to the Universal Limits section of the SPIR-V Spec (2.17), the
number of global variables may not exceed 65,535 and the number of local
variables may not exceed 524,287.
Also added unit tests for each one.
According to the SPIR-V spec (section 2.17: Universal Limits), the
OpTypeFunction instruction may not take more than 255 arguments for the
function. Also added unit tests for it.
The number of (literal, label) pairs passed to OpSwitch may not exceed
16,383. Added code to validate this and added unit tests for it.
Also fixed a typo in another validor error message.
This is described in Section 2.17 of the SPIR-V Spec.
* Updated existing unit test 'SemanticsIdIsAnIdNotALiteral' to pass by
manipulating the ID bound in its binary header.
* Fixed boundary check in the code.
* Added unit test to check the case that the largest ID is equal to the
ID bound.
