x64: Migrate brff and I128 branching instructions to ISLE (#4599)

https://github.com/bytecodealliance/wasmtime/pull/4599

cranelift/codegen/src/isa/x64/inst/args.rs

@@ -701,12 +701,6 @@ pub enum AluRmiROpcode {
     Xor,
     /// The signless, non-extending (N x N -> N, for N in {32,64}) variant.
     Mul,
-    /// 8-bit form of And. Handled separately as we don't have full 8-bit op
-    /// support (we just use wider instructions). Used only with some sequences
-    /// with SETcc.
-    And8,
-    /// 8-bit form of Or.
-    Or8,
 }
 
 impl fmt::Debug for AluRmiROpcode {
@@ -720,8 +714,6 @@ impl fmt::Debug for AluRmiROpcode {
             AluRmiROpcode::Or => "or",
             AluRmiROpcode::Xor => "xor",
             AluRmiROpcode::Mul => "imul",
-            AluRmiROpcode::And8 => "and",
-            AluRmiROpcode::Or8 => "or",
         };
         write!(fmt, "{}", name)
     }
@@ -733,16 +725,6 @@ impl fmt::Display for AluRmiROpcode {
     }
 }
 
-impl AluRmiROpcode {
-    /// Is this a special-cased 8-bit ALU op?
-    pub fn is_8bit(self) -> bool {
-        match self {
-            AluRmiROpcode::And8 | AluRmiROpcode::Or8 => true,
-            _ => false,
-        }
-    }
-}
-
 #[derive(Clone, PartialEq)]
 pub enum UnaryRmROpcode {
     /// Bit-scan reverse.
@@ -1704,32 +1686,6 @@ impl CC {
         }
     }
 
-    pub(crate) fn from_floatcc(floatcc: FloatCC) -> Self {
-        match floatcc {
-            FloatCC::Ordered => CC::NP,
-            FloatCC::Unordered => CC::P,
-            // Alias for NE
-            FloatCC::OrderedNotEqual => CC::NZ,
-            // Alias for E
-            FloatCC::UnorderedOrEqual => CC::Z,
-            // Alias for A
-            FloatCC::GreaterThan => CC::NBE,
-            // Alias for AE
-            FloatCC::GreaterThanOrEqual => CC::NB,
-            FloatCC::UnorderedOrLessThan => CC::B,
-            FloatCC::UnorderedOrLessThanOrEqual => CC::BE,
-            FloatCC::Equal
-            | FloatCC::NotEqual
-            | FloatCC::LessThan
-            | FloatCC::LessThanOrEqual
-            | FloatCC::UnorderedOrGreaterThan
-            | FloatCC::UnorderedOrGreaterThanOrEqual => panic!(
-                "{:?} can't be lowered to a CC code; treat as special case.",
-                floatcc
-            ),
-        }
-    }
-
     pub(crate) fn get_enc(self) -> u8 {
         self as u8
     }