Turn an unmatched ]] back into two ]

Needed to handle e.g. `a[a[0]]`.  SWIG's parser doesn't seem to handle
that currently though.  See #2286.

Examples/test-suite/cpp11_attribute_specifiers.i

@@ -40,4 +40,11 @@ struct [[nodiscard]] S { };
 
 const char *test_string_literal() { return "Test [[ and ]] in string literal"; }
 
+#if 0
+// Check that SWIG doesn't choke on ]] when it's not part of an attribute.
+// FIXME: SWIG's parser doesn't handle this case currently.
+int *a;
+int b = a[a[0]];
+#endif
+
 %}

Source/CParse/cscanner.c

@@ -364,7 +364,9 @@ static int yylook(void) {
       break;
 
     case SWIG_TOKEN_RRBRACKET:
-      return RRBRACKET;
+      /* Turn an unmatched ]] back into two ] - e.g. `a[a[0]]` */
+      scanner_next_token(RBRACKET);
+      return RBRACKET;
 
       /* Look for multi-character sequences */
       

Source/CParse/parser.y

@@ -1613,7 +1613,6 @@ static String *add_qualifier_to_declarator(SwigType *type, SwigType *qualifier)
 %token <type> TYPE_INT TYPE_UNSIGNED TYPE_SHORT TYPE_LONG TYPE_FLOAT TYPE_DOUBLE TYPE_CHAR TYPE_WCHAR TYPE_VOID TYPE_SIGNED TYPE_BOOL TYPE_COMPLEX TYPE_TYPEDEF TYPE_RAW TYPE_NON_ISO_INT8 TYPE_NON_ISO_INT16 TYPE_NON_ISO_INT32 TYPE_NON_ISO_INT64
 %token LPAREN RPAREN COMMA SEMI EXTERN INIT LBRACE RBRACE PERIOD ELLIPSIS
 %token CONST_QUAL VOLATILE REGISTER STRUCT UNION EQUAL SIZEOF MODULE LBRACKET RBRACKET
-%token LLBRACKET RRBRACKET  /* C++11 Attribute specifier sequence */
 %token BEGINFILE ENDOFFILE
 %token ILLEGAL CONSTANT
 %token NAME RENAME NAMEWARN EXTEND PRAGMA FEATURE VARARGS