[llvm] RuntimeLibcalls: Really move default libcall handling to tablegen (PR #148780)

[Trevor Gross via llvm-commits]

tgross35 wrote:

> AVR also has the strange reuse of the f64 names for the f32 sin and cos

I haven’t looked but would guess this platform and MSP have pretty much the same issue as f128 on 32-bit/x86, since `float` and `double` are the same size. If there was a way to indicate that a C23 math library was available (from the other PR threads), some of this could be resolved by always emitting `sqrtf32` and `sqrtf64` for binary32 and binary64 float.

Not that many people are using f64/f128 on AVR, some of the math routines are the entire flash space…

https://github.com/llvm/llvm-project/pull/148780