ManyFunctions performance test: replace xor with correct exp operator

test/ManyFunctionsGenerator.py

@@ -7,14 +7,14 @@ i = 1
 template = """
     function right{0}(uint seed) returns (uint) {{
         var r = nextRand(seed);
-        if (r >= 2^{2})
+        if (r >= 2**{2})
             return right{1}(r);
         return left{1}(r);
     }}
     
     function left{0}(uint seed) returns (uint) {{
         var r = nextRand(nextRand(seed));
-        if (r >= 2^{2})
+        if (r >= 2**{2})
             return left{1}(r);
         return right{1}(r);
     }}