PPC: [turbofan] Enable tail calls for %_CallRuntime.

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

Index: src/compiler/ppc/instruction-selector-ppc.cc
diff --git a/src/compiler/ppc/instruction-selector-ppc.cc b/src/compiler/ppc/instruction-selector-ppc.cc
index 300e27fe6f07aca3be7d0981566000132a3e55d7..339184d193106270f2c22f965b4ff7edb867ed2c 100644
--- a/src/compiler/ppc/instruction-selector-ppc.cc
+++ b/src/compiler/ppc/instruction-selector-ppc.cc
@@ -1520,9 +1520,7 @@ void InstructionSelector::VisitTailCall(Node* node) {
   DCHECK_EQ(0, descriptor->flags() & CallDescriptor::kNeedsNopAfterCall);
 
   // TODO(turbofan): Relax restriction for stack parameters.
-  if (descriptor->UsesOnlyRegisters() &&
-      descriptor->HasSameReturnLocationsAs(
-          linkage()->GetIncomingDescriptor())) {
+  if (linkage()->GetIncomingDescriptor()->CanTailCall(node)) {
     CallBuffer buffer(zone(), descriptor, nullptr);
 
     // Compute InstructionOperands for inputs and outputs.
@@ -1531,8 +1529,6 @@ void InstructionSelector::VisitTailCall(Node* node) {
     // heuristics in the register allocator for where to emit constants.
     InitializeCallBuffer(node, &buffer, true, false);
 
-    DCHECK_EQ(0u, buffer.pushed_nodes.size());
-
     // Select the appropriate opcode based on the call type.
     InstructionCode opcode;
     switch (descriptor->kind()) {