Cranelift: update to latest regalloc2: (#4324)

- Handle call instructions' clobbers with the clobbers API, using RA2's
  clobbers bitmask (bytecodealliance/regalloc2#58) rather than clobbers
  list;

- Pull in changes from bytecodealliance/regalloc2#59 for much more sane
  edge-case behavior w.r.t. liverange splitting.

cranelift/codegen/src/isa/x64/inst.isle

@@ -315,15 +315,11 @@
 
        ;; Direct call: call simm32.
        (CallKnown (dest ExternalName)
-                  (uses VecReg)
-                  (defs VecWritableReg)
-                  (opcode Opcode))
+                  (info BoxCallInfo))
 
        ;; Indirect call: callq (reg mem)
        (CallUnknown (dest RegMem)
-                    (uses VecReg)
-                    (defs VecWritableReg)
-                    (opcode Opcode))
+                    (info BoxCallInfo))
 
        ;; Return.
        (Ret (rets VecReg))
@@ -502,6 +498,8 @@
             LFence
             SFence))
 
+(type BoxCallInfo extern (enum))
+
 ;; Get the `OperandSize` for a given `Type`, rounding smaller types up to 32 bits.
 (decl operand_size_of_type_32_64 (Type) OperandSize)
 (extern constructor operand_size_of_type_32_64 operand_size_of_type_32_64)