[libc] Correct rounding for hexadecimalStringToFloat with long inputs.

Update binaryExpTofloat so that it will round correctly for long inputs when converting hexadecimal strings to floating points.

Differential Revision: https://reviews.llvm.org/D113815

GitOrigin-RevId: 201cc2d885287c91127d23ffe6f30472e974b2dc
2 files changed