Add new zero size array test. (#6379)

Closes #2890

Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

Author: mkeshavaNV

tests/diagnostics/array-zero-size.slang

@@ -0,0 +1,13 @@
+// array-zero-size.slang
+
+// Test that array size cannot be zero
+
+//TEST:SIMPLE:
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    bar();
+}
+
+func bar() -> int[0];  // expected-error 30025 "array size must be larger than zero."