x64: Take SIGFPE signals for divide traps (#6026)

* x64: Take SIGFPE signals for divide traps

Prior to this commit Wasmtime would configure `avoid_div_traps=true`
unconditionally for Cranelift. This, for the division-based
instructions, would change emitted code to explicitly trap on trap
conditions instead of letting the `div` x86 instruction trap.

There's no specific reason for Wasmtime, however, to specifically avoid
traps in the `div` instruction. This means that the extra generated
branches on x86 aren't necessary since the `div` and `idiv` instructions
already trap for similar conditions as wasm requires.

This commit instead disables the `avoid_div_traps` setting for
Wasmtime's usage of Cranelift. Subsequently the codegen rules were
updated slightly:

* When `avoid_div_traps=true`, traps are no longer emitted for `div`
  instructions.
* The `udiv`/`urem` instructions now list their trap as divide-by-zero
  instead of integer overflow.
* The lowering for `sdiv` was updated to still explicitly check for zero
  but the integer overflow case is deferred to the instruction itself.
* The lowering of `srem` no longer checks for zero and the listed trap
  for the `div` instruction is a divide-by-zero.

This means that the codegen for `udiv` and `urem` no longer have any
branches. The codegen for `sdiv` removes one branch but keeps the
zero-check to differentiate the two kinds of traps. The codegen for
`srem` removes one branch but keeps the -1 check since the semantics of
`srem` mismatch with the semantics of `idiv` with a -1 divisor
(specifically for INT_MIN).

This is unlikely to have really all that much of a speedup but was
something I noticed during #6008 which seemed like it'd be good to clean
up. Plus Wasmtime's signal handling was already set up to catch
`SIGFPE`, it was just never firing.

* Remove the `avoid_div_traps` cranelift setting

With no known users currently removing this should be possible and helps
simplify the x64 backend.

* x64: GC more support for avoid_div_traps

Remove the `validate_sdiv_divisor*` pseudo-instructions and clean up
some of the ISLE rules now that `div` is allowed to itself trap
unconditionally.

* x64: Store div trap code in instruction itself

* Keep divisors in registers, not in memory

Don't accidentally fold multiple traps together

* Handle EXC_ARITHMETIC on macos

* Update emit tests

* Update winch and tests

crates/runtime/src/traphandlers/macos.rs

@@ -244,7 +244,7 @@ unsafe fn handle_exception(request: &mut ExceptionRequest) -> bool {
     // First make sure that this exception is one that we actually expect to
     // get raised by wasm code. All other exceptions we safely ignore.
     match request.body.exception as u32 {
-        EXC_BAD_ACCESS | EXC_BAD_INSTRUCTION => {}
+        EXC_BAD_ACCESS | EXC_BAD_INSTRUCTION | EXC_ARITHMETIC => {}
         _ => return false,
     }
 
@@ -424,7 +424,7 @@ pub fn lazy_per_thread_init() {
         let this_thread = mach_thread_self();
         let kret = thread_set_exception_ports(
             this_thread,
-            EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION,
+            EXC_MASK_BAD_ACCESS | EXC_MASK_BAD_INSTRUCTION | EXC_MASK_ARITHMETIC,
             WASMTIME_PORT,
             EXCEPTION_DEFAULT | MACH_EXCEPTION_CODES,
             mach_addons::THREAD_STATE_NONE,