S390x: emit new instructions added in z17 (#12319)

* s390x: Emit instructions from MIE4 & VXRS_EXT3 on z17

This emits & tests a bunch of instructions:
  * from Miscellaneous-Instruction-Extensions Facility 4:
    * CLZ, 64bit
    * CTZ, 64bit
  * from Vector-Enhancements Facility 3:
    * 32x4, 64x2 & 128x1 variants of the following:
      * Divide
      * Remainder
    * 64x2 & 128x1 multiply variants
    * 128x1 vaiants of:
      * Compare
      * CLZ
      * CTZ
      * Max
      * Min
      * Average
      * Negation
      * Evaluate

Co-authored-by: Jimmy Brisson <[email protected]>

* s390x: Emit vector blend on z17

* Rename x86_blendv to blendv

Now that s390x implements blendv as well, we should refer to
the instruction without the x86 prefix.

---------

Co-authored-by: Ulrich Weigand <[email protected]>

Author: theotherjimmy

cranelift/codegen/meta/src/shared/instructions.rs

@@ -1667,7 +1667,7 @@ pub(crate) fn define(
 
     ig.push(
         Inst::new(
-            "x86_blendv",
+            "blendv",
             r#"
         A bitselect-lookalike instruction except with the semantics of
         `blendv`-related instructions on x86.

cranelift/codegen/src/isa/aarch64/mod.rs

@@ -227,7 +227,7 @@ impl TargetIsa for AArch64Backend {
         true
     }
 
-    fn has_x86_blendv_lowering(&self, _: Type) -> bool {
+    fn has_blendv_lowering(&self, _: Type) -> bool {
         false
     }
 

cranelift/codegen/src/isa/mod.rs

@@ -391,9 +391,9 @@ pub trait TargetIsa: fmt::Display + Send + Sync {
     /// Returns whether this ISA has instructions for `ceil`, `floor`, etc.
     fn has_round(&self) -> bool;
 
-    /// Returns whether the CLIF `x86_blendv` instruction is implemented for
+    /// Returns whether the CLIF `blendv` instruction is implemented for
     /// this ISA for the specified type.
-    fn has_x86_blendv_lowering(&self, ty: Type) -> bool;
+    fn has_blendv_lowering(&self, ty: Type) -> bool;
 
     /// Returns whether the CLIF `x86_pshufb` instruction is implemented for
     /// this ISA.

cranelift/codegen/src/isa/pulley_shared/mod.rs

@@ -232,7 +232,7 @@ where
         true
     }
 
-    fn has_x86_blendv_lowering(&self, _ty: ir::Type) -> bool {
+    fn has_blendv_lowering(&self, _ty: ir::Type) -> bool {
         false
     }
 

cranelift/codegen/src/isa/riscv64/mod.rs

@@ -205,7 +205,7 @@ impl TargetIsa for Riscv64Backend {
         true
     }
 
-    fn has_x86_blendv_lowering(&self, _: Type) -> bool {
+    fn has_blendv_lowering(&self, _: Type) -> bool {
         false
     }