100000000000000000000000.000000000000001 is 1e+23 instead of 1.0000000000000001e+23 #452

I bisected this to 9936606

Before this commit, quickjs matches other engines and prints 1.0000000000000001e+23, but after, it prints 1e+23.

(Found the same way as #449, but I mistakenly though it was a ccgo bug because I had not tested master here. Oops.)