PPC/s390: [ptr-compr] Remove Compressed mentions from in the pipeline

Port 6e90f2f2

Original Commit Message:

    Including but not limiting to removing:
     * BitcastCompressedXXX
     * CheckedCompressedXXX
     * ChangeXXXToCompressedYYY
     * ChangeCompressedXXX

    As a note, ChangeTaggedToCompressed can't be removed just yet as it
    is still in use.

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

Change-Id: I0974b300654f61d152ea65016a0e278ea4ba1b60
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1907440Reviewed-by: Junliang Yan <jyan@ca.ibm.com>
Commit-Queue: Milad Farazmand <miladfar@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#64885}

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

@@ -1168,30 +1168,6 @@ void InstructionSelector::VisitChangeTaggedToCompressed(Node* node) {
   UNIMPLEMENTED();
 }
 
-void InstructionSelector::VisitChangeTaggedPointerToCompressedPointer(
-    Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitChangeTaggedSignedToCompressedSigned(
-    Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitChangeCompressedToTagged(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitChangeCompressedPointerToTaggedPointer(
-    Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitChangeCompressedSignedToTaggedSigned(
-    Node* node) {
-  UNIMPLEMENTED();
-}
-
 void InstructionSelector::VisitChangeFloat64ToUint64(Node* node) {
   VisitRR(this, kPPC_DoubleToUint64, node);
 }

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

@@ -2247,30 +2247,6 @@ void InstructionSelector::VisitChangeTaggedToCompressed(Node* node) {
   UNIMPLEMENTED();
 }
 
-void InstructionSelector::VisitChangeTaggedPointerToCompressedPointer(
-    Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitChangeTaggedSignedToCompressedSigned(
-    Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitChangeCompressedToTagged(Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitChangeCompressedPointerToTaggedPointer(
-    Node* node) {
-  UNIMPLEMENTED();
-}
-
-void InstructionSelector::VisitChangeCompressedSignedToTaggedSigned(
-    Node* node) {
-  UNIMPLEMENTED();
-}
-
 void InstructionSelector::VisitWord32AtomicLoad(Node* node) {
   LoadRepresentation load_rep = LoadRepresentationOf(node->op());
   DCHECK(load_rep.representation() == MachineRepresentation::kWord8 ||