[WGSL] Add missing tests for 270436@main

https://bugs.webkit.org/show_bug.cgi?id=264497
rdar://118180741

Reviewed by Mike Wyrzykowski.

For some reason the test wasn't included in the original commit.

* Source/WebGPU/WGSL/tests/invalid/constants.wgsl: Added.

Canonical link: https://commits.webkit.org/270521@main

Source/WebGPU/WGSL/tests/invalid/constants.wgsl

@@ -0,0 +1,44 @@
+// RUN: %not %wgslc | %check
+
+
+fn testOutOfBounds()
+{
+    {
+        const x = array(0);
+        // CHECK-L: index -1 is out of bounds [0..0]
+        _ = x[-1];
+        // CHECK-NOT-L: index 0 is out of bounds [0..0]
+        _ = x[0];
+        // CHECK-L: index 1 is out of bounds [0..0]
+        _ = x[1];
+    }
+
+    {
+        const x = mat2x2(0, 0, 0, 0);
+        // CHECK-L: index -1 is out of bounds [0..1]
+        _ = x[-1];
+        // CHECK-NOT-L: index 0 is out of bounds [0..1]
+        _ = x[0];
+        // CHECK-NOT-L: index 1 is out of bounds [0..1]
+        _ = x[1];
+        // CHECK-L: index 2 is out of bounds [0..1]
+        _ = x[2];
+    }
+
+    {
+        const x = vec2(0);
+        // CHECK-L: index -1 is out of bounds [0..1]
+        _ = x[-1];
+        // CHECK-NOT-L: index 0 is out of bounds [0..1]
+        _ = x[0];
+        // CHECK-NOT-L: index 1 is out of bounds [0..1]
+        _ = x[1];
+        // CHECK-L: index 2 is out of bounds [0..1]
+        _ = x[2];
+    }
+}
+
+fn main()
+{
+    testOutOfBounds();
+}