Add CP437 0xDB - 0xDF (FULL/HALF block) enum definitions.

src/xpdev/cp437defs.h

@@ -130,6 +130,12 @@ enum cp437_char {
 	CP437_BOX_DRAWINGS_DOUBLE_VERTICAL = '\xBA',
 	CP437_BOX_DRAWINGS_VERTICAL_AND_HORIZONTAL = '\xC5',
 	// TODO...
+	CP437_FULL_BLOCK = '\xDB',
+	CP437_LOWER_HALF_BLOCK = '\xDC',
+	CP437_LEFT_HALF_BLOCK = '\xDD',
+	CP437_RIGHT_HALF_BLOCK = '\xDE',
+	CP437_UPPER_HALF_BLOCK = '\xDF',
+	// TODO...
 	CP437_GREEK_SMALL_LETTER_ALPHA = '\xE0',
 	CP437_GREEK_SMALL_LETTER_BETA = '\xE1',
 	CP437_LATIN_SMALL_LETTER_SHARP_S = '\xE1',		// Duplicate