Disallow invalid values inside jsx when a fragment is expected

For example, the following used to compile:
`jsx('<div>${function() return 42}</div>');`

But resulted in a runtime error:
> Warning: Functions are not valid as a React child. This may happen if you
> return a Component instead of <Component /> from render. Or maybe you meant
> to call this function rather than return it.

Or, for objects: `jsx('<div>${{test: 42}}</div>');` resulted in:
> Uncaught Error: Objects are not valid as a React child (found: object with
> keys {test}). If you meant to render a collection of children,
> use an array instead.

Author: kLabz

src/lib/react/ReactComponent.hx

@@ -118,6 +118,8 @@ typedef ReactFragment = EitherType<
 	ReactElement,
 	EitherType<
 		Array<ReactFragment>,
-		EitherType<String, Float>
+		EitherType<String,
+			EitherType<Float, Bool>
+		>
 	>
 >;

src/lib/react/ReactMacro.hx

@@ -182,7 +182,8 @@ class ReactMacro
 	{
 		return switch (c.value) {
 			case CText(s): macro @:pos(s.pos) $v{replaceEntities(s.value, s.pos)};
-			case CExpr(e): e;
+			case CExpr(e):
+				macro @:pos(e.pos) (${e} :react.ReactComponent.ReactFragment);
 			case CNode(n):
 				var type = switch (n.name.value.split('.')) {
 					case [tag] if (tag.charAt(0) == tag.charAt(0).toLowerCase()):