FIX/CHANGE: removed recently added NAN? native and replaced NUMBER? function with native equivalent which properly checks if decimal value is not a NAN

Previously:
```
>> number? 1.#NaN
== true
```

Now it is `false` (which is logical as NaN means _Not a Number_)

Although 1.#NaN is not a number, it is still of type DECIMAL!
```
>> type? 1.#NaN
== decimal!

```

Author: Oldes

src/core/n-math.c

@@ -303,23 +303,33 @@ enum {SINE, COSINE, TANGENT};
 	return R_RET;
 }
 
+#endif //!USE_NO_INFINITY
+
 /***********************************************************************
 **
-*/	REBNATIVE(nanq)
+*/	REBNATIVE(numberq)
 /*
-//	nan?: native [
-//		{Returns TRUE if the number is Not-a-Number.}
-//		value [number!]
+//	number?: native [
+//		{Returns TRUE if the value is any type of number and not a NaN. }
+//		value
 //	]
 ***********************************************************************/
 {
-	SET_LOGIC(D_RET, isnan(AS_DECIMAL(D_ARG(1))));
+	BOOL result = FALSE;
+	switch(VAL_TYPE(D_ARG(1))) {
+		case REB_DECIMAL:
+			if (!isnan(VAL_DECIMAL(D_ARG(1)))) result = TRUE;
+			break;
+		case REB_INTEGER:
+		case REB_MONEY:
+		case REB_PERCENT:
+			result = TRUE;
+			break;
+	}
+	SET_LOGIC(D_RET, result);
 	return R_RET;
 }
 
-#endif //!USE_NO_INFINITY
-
-
 
 /***********************************************************************
 **

src/mezz/base-defs.r

@@ -118,10 +118,11 @@ any-object?: func [
 	value [any-type!]
 ][find any-object! type? :value]
 
-number?: func [
-	"Return TRUE if value is a number (integer or decimal)."
-	value [any-type!]
-][find number! type? :value]
+;@@ Oldes: replaced with native version - n-math.c (which handles NaN values too)
+;number?: func [
+;	"Return TRUE if value is a number (integer or decimal)."
+;	value [any-type!]
+;][find number! type? :value]
 
 series?: func [
 	"Return TRUE if value is any type of series."