PPC/s390: [wasm-simd][liftoff] Implement i16x8.splat on X64 and IA32

Port 59e96890

R=zhiguo.zhou@intel.com, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=
LOG=N

Change-Id: I01be626d6017d0d76daffc281f64352e3b8ead2b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2062248Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#66310}

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

@@ -527,6 +527,11 @@ void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
   bailout(kUnsupportedArchitecture, "emit_i32x4_splat");
 }
 
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "i16x8splat");
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   bailout(kUnsupportedArchitecture, "StackCheck");
 }

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

@@ -531,6 +531,11 @@ void LiftoffAssembler::emit_i32x4_splat(LiftoffRegister dst,
   bailout(kUnsupportedArchitecture, "emit_i32x4_splat");
 }
 
+void LiftoffAssembler::emit_i16x8_splat(LiftoffRegister dst,
+                                        LiftoffRegister src) {
+  bailout(kUnsupportedArchitecture, "i16x8splat");
+}
+
 void LiftoffAssembler::StackCheck(Label* ool_code, Register limit_address) {
   bailout(kUnsupportedArchitecture, "StackCheck");
 }