FEAT: Allow direct conversion from tag! to word! (if it has valid chars)

resolves: Oldes/Rebol-wishes#2

Author: Oldes

src/core/t-word.c

@@ -98,7 +98,7 @@
 			return R_ARG2;
 		}
 		else {
-			if (IS_STRING(arg) || IS_REF(arg)) {
+			if (IS_STRING(arg) || IS_REF(arg) || IS_TAG(arg)) {
 				REBYTE *bp;
 				REBCNT len;
 				// Set sym. Rest is set below.

src/tests/units/word-test.r3

@@ -20,6 +20,11 @@ Rebol [
 	--assert 1 = length? to-word to-string to-char 126
 	--assert 1 = length? to-word to-string to-char 128
 
+	--test-- "Word from tag"
+	;@@ https://github.com/Oldes/Rebol-wishes/issues/2
+	--assert 'a = to word! <a>
+	--assert error? try [to word! <a b>]
+
 ===end-group===
 
 ===start-group=== "word compare"