Fix clang20+ compilation

[KaperD]

Since clang 20 there is overriding-option check, which fails if both -ffp-model=precise and -ffp-contract=off are set (they are for AppleClang e.g.). Example https://godbolt.org/z/eWMn4c7z9

From clang docs: precise Disables optimizations that are not value-safe on floating-point data, although FP contraction (FMA) is enabled (-ffp-contract=on). This is the default behavior. This value resets -fmath-errno to its target-dependent default.

So, -ffp-model=precise = -fno-unsafe-math-optimizations -ffp-contract=on + reset -fmath-errno. But you don't use errno, that is why we can change -ffp-model=precise to -fno-unsafe-math-optimizations`

[solidpixel]

Thanks for the heads up and the PR - will take a look.