PPC/s390: fix compilation error

Change-Id: I060905ed0954365e64c45f7bac53909256f35c0c
Reviewed-on: https://chromium-review.googlesource.com/c/1405910Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#58747}

src/compiler/backend/ppc/instruction-selector-ppc.cc

@@ -2344,6 +2344,8 @@ void InstructionSelector::VisitI8x16ShrU(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitI8x16Mul(Node* node) { UNIMPLEMENTED(); }
 
+void InstructionSelector::VisitS8x16Shuffle(Node* node) { UNIMPLEMENTED(); }
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {

src/compiler/backend/s390/instruction-selector-s390.cc

@@ -2744,6 +2744,8 @@ void InstructionSelector::VisitI8x16ShrU(Node* node) { UNIMPLEMENTED(); }
 
 void InstructionSelector::VisitI8x16Mul(Node* node) { UNIMPLEMENTED(); }
 
+void InstructionSelector::VisitS8x16Shuffle(Node* node) { UNIMPLEMENTED(); }
+
 // static
 MachineOperatorBuilder::Flags
 InstructionSelector::SupportedMachineOperatorFlags() {