PPC/s390: Reland "[liftoff][wasm-simd] Implement f32x4.splat"

Port b110d480

Original Commit Message:

    This relands commit 009993ad.

    The fix is in liftoff-assembler-ia32.h, the codegen was incorrect.

    Original change's description:
    > Implement f32x4.splat and enable handling this in Liftoff.
    >
    > We add a new macro for defining test cases to run on TurboFan, Liftoff,
    > interpreter, and scalar lowering.
    >
    > Also add an assertion that the execution tier used is what we expected
    > it to be. This is useful for Liftoff, because by default it falls back
    > to TurboFan when it encounters an unimplemented opcode.
    >
    > Bug: v8:9909

R=zhin@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: I0fc54cd04379a6c65aa2bee64bf4cf9dad5b9636
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2019582Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#65977}

src/wasm/baseline/ppc/liftoff-assembler-ppc.h

@@ -493,6 +493,11 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   bailout(kUnsupportedArchitecture, "emit_f64_set_cond");
 }
 
+void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4_splat");
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   bailout(kUnsupportedArchitecture, "StackCheck");
 }

src/wasm/baseline/s390/liftoff-assembler-s390.h

@@ -497,6 +497,11 @@ void LiftoffAssembler::emit_f64_set_cond(Condition cond, Register dst,
   bailout(kUnsupportedArchitecture, "emit_f64_set_cond");
 }
 
+void LiftoffAssembler::emit_f32x4_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "emit_f32x4_splat");
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   bailout(kUnsupportedArchitecture, "StackCheck");
 }