Include ASCII characters in "na" table

Since we're now assigning "na" (narrow) characters width 1,
we can include the ASCII character ranges in the table.

Author: wedaly

runewidth_table.go

@@ -44,7 +44,7 @@ var tables = []tableInfo{
 	{doublewidth, "doublewidth", 182440, "3d16eda8650dc2c92d6318d32f0b4a74fda5a278db2d4544b1dd65863394823c"},
 	{ambiguous, "ambiguous", 138739, "d05e339a10f296de6547ff3d6c5aee32f627f6555477afebd4a3b7e3cf74c9e3"},
 	{emoji, "emoji", 3535, "9ec17351601d49c535658de8d129c1d0ccda2e620669fc39a2faaee7dedcef6d"},
-	{narrow, "narrow", 10, "68441e98eca1450efbe857ac051fcc872eed347054dfd0bc662d1c4ee021d69f"},
+	{narrow, "narrow", 111, "fa897699c5e3cd9141c638d539331b0bdd508b874e22996c5e929767d455fc5a"},
 	{neutral, "neutral", 27333, "5455f5e75c307f70b4e9b2384dc5a8bcd91a4c5e2b24b2b185dfad4d860ee5c2"},
 }
 
@@ -164,6 +164,7 @@ var runewidthtests = []struct {
 	{'\u0300', 0, 0},
 	{'\u2028', 0, 0},
 	{'\u2029', 0, 0},
+	{'a', 1, 1}, // ASCII classified as "na" (narrow)
 	{'⟦', 1, 1}, // non-ASCII classified as "na" (narrow)
 }
 

runewidth_test.go

@@ -92,12 +92,10 @@ func eastasian(out io.Writer, in io.Reader) error {
 				hi: r2,
 			})
 		case "Na":
-			if r1 > 0xFF {
-				na = append(na, rrange{
-					lo: r1,
-					hi: r2,
-				})
-			}
+			na = append(na, rrange{
+				lo: r1,
+				hi: r2,
+			})
 		case "N":
 			nu = append(nu, rrange{
 				lo: r1,