Made C's sizeof operator work with initialized void variables.

Added regression tests that check cc65's handling of void variables.

src/cc65/datatype.c

@@ -389,7 +389,10 @@ unsigned SizeOf (const Type* T)
     switch (UnqualifiedType (T->C)) {
 
         case T_VOID:
-            return 0;   /* Assume voids have size zero */
+            /* A void variable is a cc65 extension.
+            ** Get its size (in bytes).
+            */
+            return T->A.U;
 
         /* Beware: There's a chance that this triggers problems in other parts
            of the compiler. The solution is to fix the callers, because calling
@@ -438,7 +441,7 @@ unsigned SizeOf (const Type* T)
                 /* Array with unspecified size */
                 return 0;
             } else {
-                return T->A.L * SizeOf (T + 1);
+                return T->A.U * SizeOf (T + 1);
             }
 
         default:

src/cc65/declare.c

@@ -891,6 +891,7 @@ static void ParseTypeSpec (DeclSpec* D, long Default, TypeCode Qualifiers)
         case TOK_VOID:
             NextToken ();
             D->Type[0].C = T_VOID;
+            D->Type[0].A.U = 0;
             D->Type[1].C = T_END;
             break;
 
@@ -2114,7 +2115,7 @@ NextMember:
 
 
 
-static unsigned ParseVoidInit (void)
+static unsigned ParseVoidInit (Type* T)
 /* Parse an initialization of a void variable (special cc65 extension).
 ** Return the number of bytes initialized.
 */
@@ -2181,6 +2182,9 @@ static unsigned ParseVoidInit (void)
     /* Closing brace */
     ConsumeRCurly ();
 
+    /* Number of bytes determined by initializer */
+    T->A.U = Size;
+
     /* Return the number of bytes initialized */
     return Size;
 }
@@ -2216,8 +2220,8 @@ static unsigned ParseInitInternal (Type* T, int AllowFlexibleMembers)
 
         case T_VOID:
             if (IS_Get (&Standard) == STD_CC65) {
-                /* Special cc65 extension in non ANSI mode */
-                return ParseVoidInit ();
+                /* Special cc65 extension in non-ANSI mode */
+                return ParseVoidInit (T);
             }
             /* FALLTHROUGH */