PPC: [turbofan] Add initial support for SOFT deopts.

Port 7a22fdff

Original commit message:
    This only introduces the basic support for both SOFT and EAGER deopts in
    TurboFan, but doesn't make use of SOFT deopts anywhere yet (there are
    some other issues blocking that). Basically every Deoptimize operator
    now has a DeoptimizeKind, which can be either kSoft or kEager.

R=bmeurer@chromium.org, joransiu@ca.ibm.com, jyan@ca.ibm.com, michael_dawson@ca.ibm.com
BUG=

Review URL: https://codereview.chromium.org/1518483002

Cr-Commit-Position: refs/heads/master@{#32727}

src/compiler/ppc/code-generator-ppc.cc

@@ -761,7 +761,9 @@ void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
     case kArchDeoptimize: {
       int deopt_state_id =
           BuildTranslation(instr, -1, 0, OutputFrameStateCombine::Ignore());
-      AssembleDeoptimizerCall(deopt_state_id, Deoptimizer::EAGER);
+      Deoptimizer::BailoutType bailout_type =
+          Deoptimizer::BailoutType(MiscField::decode(instr->opcode()));
+      AssembleDeoptimizerCall(deopt_state_id, bailout_type);
       break;
     }
     case kArchRet: