Add parser testcases

syntax/array_keyword.invalid.mj

+class Arrays {
+    public package[] foo;
+}
\ No newline at end of file

syntax/assigning_null.mj

+class A {
+    void nullAssigner() {
+        null = this;
+        null = 3;
+        null = abc;
+    }
+}
\ No newline at end of file

syntax/block_statement_vs_expression.mj

+class Foo {
+    /* Array definition vs access */
+    public void bar() {
+        abc[1];
+        abc[] def;
+    }
+
+}
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syntax/different_returns.mj

+class Return {
+
+public void foo0(int x, int y) { return; }
+public void foo1(int x, int y) { return x + y; }
+public void foo1(int x, int y) { return (x = 3); }
+
+}
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syntax/interface.invalid.mj

+interface Foo {}
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syntax/method_multiple_brackets.invalid.mj

+class A {
+    public int b()() {}
+}
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syntax/method_not_public.invalid.mj

+class TopSecret {
+    public int solution = 0;
+
+    int actualSolution()  {
+        return 42;
+    }
+
+}
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syntax/method_two_types.invalid.mj

+class A {
+    void int a() {}
+}
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syntax/method_with_semicolon.invalid.mj

+class A {
+    public int b() {};
+}
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syntax/nested_loops.mj

+class NestedLoop {
+    public void foo() {
+        int i = 0;
+        while(x != y) {
+            while(x != y) {
+                while(x != y) {
+                    while(x != y) {
+                        while(x != y) {
+                            while(x != y) {
+                                while(x != y) {
+                                    while(x != y) {
+                                        while(x != y) {
+                                            while(x != y) {
+                                                while(x != y) {
+                                                    while(x != y) {
+                                                    }
+                                                }
+                                            }
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+

syntax/throws_keyword.invalid.mj

+class A {
+    void foo() throws package {}
+}
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