Add more (mostly invalid) syntax test cases

syntax/class_no_block.invalid.mj

+class A
\ No newline at end of file

syntax/class_no_block_semicolon.invalid.mj

+class A;
\ No newline at end of file

syntax/class_without_ident.invalid.mj

+class {}
\ No newline at end of file

syntax/field_ident_is_keyword.invalid.mj

+class Test {
+    public void class;
+}
\ No newline at end of file

syntax/field_missing_semicolon.invalid.mj

+class A {
+    public int duck
+}
\ No newline at end of file

syntax/field_private.invalid.mj

+class A {
+    private int hello;
+}
\ No newline at end of file

syntax/field_type_is_keyword.invalid.mj

+class A {
+    public while testing;
+}
\ No newline at end of file

syntax/if_else_empty.mj

+class Hi {
+public Hello Hey() {
+if(angry) {} else;
+}
+}
\ No newline at end of file

syntax/if_empty_else_empty.mj

+class Tree {
+public Leafs falling(bool really) {
+/* broken method */
+if(autumn);else;
+}
+}
\ No newline at end of file

syntax/main_as_statement.invalid.mj

+class A {
+    public static void IDENT(String[]ident);
+}
\ No newline at end of file

syntax/main_string_array_expression.invalid.mj

+class box {
+public static void method(String[5]a){}
+}
\ No newline at end of file

syntax/method_methodRest.mj

+class HowAreYou {
+public Library opening(Times incorrect) throws Exception{}
+}
\ No newline at end of file

syntax/method_missing_ident.invalid.mj

+class Noooooooo {
+public void(){}
+}
\ No newline at end of file

syntax/method_missing_parameter.invalid.mj

+class A{
+public Chicken likes(,eating corn) {}
+}
\ No newline at end of file

syntax/method_private.invalid.mj

+class Detective {
+private void method(){}
+}
\ No newline at end of file

syntax/missing_class_keyword.invalid.mj

+A {
+
+}
\ No newline at end of file