PPC: Add EmitConstantPool to FinishCode

R=joransiu@ca.ibm.com, jbarboza@ca.ibm.com, michael_dawson@ca.ibm.com

Bug: 
Change-Id: I30c5bba9380d71d1ea2fc0391aa90adca9330eb2
Reviewed-on: https://chromium-review.googlesource.com/721339Reviewed-by: Joran Siu <joransiu@ca.ibm.com>
Commit-Queue: Junliang Yan <jyan@ca.ibm.com>
Cr-Commit-Position: refs/heads/master@{#48601}

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

@@ -2425,7 +2425,7 @@ void CodeGenerator::AssembleReturn(InstructionOperand* pop) {
   __ Ret();
 }
 
-void CodeGenerator::FinishCode() {}
+void CodeGenerator::FinishCode() { __ EmitConstantPool(); }
 
 void CodeGenerator::AssembleMove(InstructionOperand* source,
                                  InstructionOperand* destination) {