Add the string to floating point conversion functions.
Long doubles aren't supported yet, but floats and doubles are. The
primary algorithm used is the Eisel-Lemire ParseNumberF64 algorithm,
with the Simple Decimal Conversion algorithm as backup.
Links for more information on the algorithms:
Number Parsing at a Gigabyte per Second, Software: Practice and
Experience 51 (8), 2021 (https://arxiv.org/abs/2101.11408)
https://nigeltao.github.io/blog/2020/eisel-lemire.html
https://nigeltao.github.io/blog/2020/parse-number-f64-simple.html
We should ideally have the script which produced these constants checked in. I encourage you to look at https://www.sollya.org/ using which one can trivially produce these constants. We can check-in sollya scripts. For example: https://github.com/llvm/llvm-project/blob/main/libc/utils/mathtools/expm1f.sollya