Fix long double and Float128 negative sign being overwritten

[mborland]

Closes: #148

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (48b7098) 88.41% compared to head (825a24b) 88.53%. Report is 16 commits behind head on develop.

Additional details and impacted files

[](https://app.codecov.io/gh/cppalliance/charconv/pull/150?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance) ```diff @@ Coverage Diff @@ ## develop #150 +/- ## =========================================== + Coverage 88.41% 88.53% +0.11% =========================================== Files 58 59 +1 Lines 7936 8033 +97 =========================================== + Hits 7017 7112 +95 - Misses 919 921 +2 ``` | [Files](https://app.codecov.io/gh/cppalliance/charconv/pull/150?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance) | Coverage Δ | | |---|---|---| | [...lude/boost/charconv/detail/ryu/ryu\_generic\_128.hpp](https://app.codecov.io/gh/cppalliance/charconv/pull/150?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance#diff-aW5jbHVkZS9ib29zdC9jaGFyY29udi9kZXRhaWwvcnl1L3J5dV9nZW5lcmljXzEyOC5ocHA=) | `82.40% <100.00%> (+0.37%)` | :arrow_up: | | [test/roundtrip.cpp](https://app.codecov.io/gh/cppalliance/charconv/pull/150?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance#diff-dGVzdC9yb3VuZHRyaXAuY3Bw) | `98.44% <100.00%> (+0.01%)` | :arrow_up: | | [test/test\_float128.cpp](https://app.codecov.io/gh/cppalliance/charconv/pull/150?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance#diff-dGVzdC90ZXN0X2Zsb2F0MTI4LmNwcA==) | `100.00% <ø> (ø)` | | ... and [5 files with indirect coverage changes](https://app.codecov.io/gh/cppalliance/charconv/pull/150/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance) ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/cppalliance/charconv/pull/150?src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/cppalliance/charconv/pull/150?src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance). Last update [48b7098...825a24b](https://app.codecov.io/gh/cppalliance/charconv/pull/150?src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=cppalliance).