Rollup merge of #107970 - hermitcore:hermit-rm-floor, r=thomcc

Hermit: Remove floor symbol

This symbol should be provided by Hermit.

It was introduced in 2019 (https://github.com/rust-lang/rust/pull/65167). Since 2020, Hermit provides these math functions on its own (https://github.com/hermitcore/rusty-hermit/pull/37). I think moving this to Hermit was merely an oversight.

Related:
* https://github.com/hermitcore/libhermit-rs/pull/654
* https://github.com/hermitcore/rusty-hermit/pull/406

CC: `@stlankes`

library/std/src/sys/hermit/mod.rs

@@ -72,11 +72,6 @@ pub fn unsupported_err() -> crate::io::Error {
     )
 }
 
-#[no_mangle]
-pub extern "C" fn floor(x: f64) -> f64 {
-    unsafe { intrinsics::floorf64(x) }
-}
-
 pub fn abort_internal() -> ! {
     unsafe {
         abi::abort();