readFloat64xx doesn't work properly

[w35l3y]

Both functions readFloat64BE and readFloat64LE are buggy at the following line:

(((b5 & 0x7F) << 24) | (b6 << 16) | (b7 << 8) | b8).toString(2)

If you do, for example:
var b5 = 0, b6 = 0, b7 = 0, b8 = 0;

The expected value should be "0000000000000000000000000000000" (31 zeros), but instead it returns "0"

I solved it by using:

("000000000000000000000000000000" + (((b5 & 0x7F) << 24) | (b6 << 16) | (b7 << 8) | b8).toString(2)).substr(-31)

But this solution isn't cross-browser.

Tested on Firefox 12.0

Thank you for your great work.