parser: fix dollar (closes #14292) (#14378)

vlib/v/parser/parser.v

@@ -663,6 +663,9 @@ pub fn (mut p Parser) top_stmt() ast.Stmt {
 				return p.struct_decl()
 			}
 			.dollar {
+				if p.peek_tok.kind == .eof {
+					return p.error('unexpected eof')
+				}
 				if_expr := p.if_expr(true)
 				return ast.ExprStmt{
 					expr: if_expr

vlib/v/parser/tests/dollar_err.out

@@ -0,0 +1,3 @@
+vlib/v/parser/tests/dollar_err.vv:1:1: error: unexpected eof, expecting `if`
+    1 | $
+      | ^

vlib/v/parser/tests/dollar_err.vv

@@ -0,0 +1 @@
+$