Add regression tests of BA issue cases (#3462)

tests/regression/ba-issues/issues/issue-315101/test.wast

@@ -0,0 +1,24 @@
+(module
+ (data $string_data "asdf")
+ (func $print (import "spectest" "print_i32") (param $i i32))
+ (memory $memory (export "memory") 1)
+ (type $string (array (mut i8)))
+ (type $var (struct (field (ref null $string))))
+
+ (func $test (param $param (ref $var))
+    (local.get $param)
+    (struct.get $var 0) 
+    (ref.as_non_null)
+    (array.len)
+    (call $print)
+ )
+ (func $init
+    (local $str (ref $string))
+    (array.new_data $string $string_data (i32.const 0) (i32.const 4))
+    (local.set $str)
+    (struct.new $var (local.get $str))
+    (call $test)
+ )
+
+ (export "_start" (func $init))
+)