Update src/tokenize.jl

Co-authored-by: Sebastian Pfitzner <[email protected]>
(cherry picked from commit 542dcd7, PR JuliaLang#553)

Author: 2 people

src/tokenize.jl

@@ -1339,7 +1339,7 @@ end
 function simple_hash(str)
     ind = 1
     h = UInt64(0)
-    L = length(str)
+    L = min(lastindex(str), MAX_KW_LENGTH)
     while ind <= L
         h = simple_hash(str[ind], h)
         ind = nextind(str, ind)