Crash when trying to convert a struct slice to a vector #2039.

test/test_suite/vector/slice_to_vector_but_not_allowed_base.c3

@@ -0,0 +1,8 @@
+// Repro issue #2039
+module foo;
+struct Foo { void* x; }
+fn void main()
+{
+	Foo* foo;
+	float[<2>] a = foo[0..1]; // #error: It is not possible to cast
+}