Add a test case for explicitly for a number larger than 2^60

I'm hypothesizing that some platforms treat long as 32bit and thus
require long long.

c_src/decoder.c

@@ -374,7 +374,7 @@ dec_number(Decoder* d, ERL_NIF_TERM* value)
     int has_frac = 0;
     int has_exp = 0;
     double dval;
-    long lval;
+    long long lval;
 
     while(d->i < d->len) {
         switch(state) {
@@ -589,7 +589,7 @@ parse:
                 return 1;
             }
         } else {
-            lval = strtol(nbuf, NULL, 10);
+            lval = strtoll(nbuf, NULL, 10);
             if(errno != ERANGE) {
                 *value = enif_make_int64(d->env, lval);
                 return 1;

test/jiffy_03_number_tests.erl

@@ -49,6 +49,7 @@ cases(ok) ->
         {<<"12">>, 12},
         {<<"-3">>, -3},
         {<<"1234567890123456789012345">>, 1234567890123456789012345},
+        {<<"4611686018427387904">>, 4611686018427387904},
         {<<"1310050760199">>, 1310050760199},
         {
             <<"1234567890123456789012345.0">>,