[snehabandla]

Summary

Arity errors in Azure Policy now name the ARM function the author wrote. Previously, more than 8 arguments to a function such as and(), or(), union() or format() reported the internal builtin name (builtin call … exceeds max 8 args). Now the error reads, for example, union() does not support more than 8 arguments (got 9).

The compiler tracks the ARM function currently being compiled in current_arm_function. It saves and restores that value around nested calls, so the error names the innermost function that overflowed.

This PR also tightens the test harness. A case with want_compile_error: false plus want_compile_error_contains, or a compile-error case that also names an effect, used to pass without checking the conflicting field. Such cases now fail.

Behavior change

The error text changes. Callers in any of the 9 bindings that match on the old message will see the new text.

Tests

tests/azure_policy/cases/builtin_arity.yaml:

• 9-argument and(), or() and union() (generic dispatch) name the ARM function.
• Uppercase function names report the lowercase ARM name.
• A nested overflow is attributed to the inner function (format()).
• An overflow after a completed nested call names the caller.
• 8-argument boundary cases still compile and evaluate, and packed concat() still accepts more than 8 arguments.
• New harness checks reject contradictory compile-error expectations.