Allow non-JNI unsafes for p codegen

In Java9 sun.misc.Unsafe JNI methods are moved to jdk.internal and
replaced with simple wrappers. This leads to a few places in the
code where we do the wrong thing by assuming that the recognized
Unsafe method is a JNI method.
This commit adds explicit tests to prevent p codegen from attempting
to transform the non-JNI versions of the unsafe CAS instructions.

Signed-off-by: James Kingdon <jkingdon@ca.ibm.com>

runtime/tr.source/trj9/p/codegen/J9TreeEvaluator.cpp

@@ -12874,6 +12874,12 @@ J9::Power::CodeGenerator::inlineDirectCall(TR::Node *node, TR::Register *&result
          break;
 
       case TR::sun_misc_Unsafe_compareAndSwapInt_jlObjectJII_Z:
+        // In Java9 this can be either the jdk.internal JNI method or the sun.misc Java wrapper.
+        // In Java8 it will be sun.misc which will contain the JNI directly.
+        // We only want to inline the JNI methods, so add an explicit test for isNative().
+        if (!methodSymbol->isNative())
+           break;
+
         if ((node->isUnsafeGetPutCASCallOnNonArray() || !TR::Compiler->om.canGenerateArraylets()) && node->isSafeForCGToFastPathUnsafeCall())
             {
             resultReg = VMinlineCompareAndSwap(node, cg, false);
@@ -12883,6 +12889,10 @@ J9::Power::CodeGenerator::inlineDirectCall(TR::Node *node, TR::Register *&result
 
       case TR::sun_misc_Unsafe_compareAndSwapLong_jlObjectJJJ_Z:
          traceMsg(comp, "In evaluator for compareAndSwapLong. node = %p node->isSafeForCGToFastPathUnsafeCall = %p\n", node, node->isSafeForCGToFastPathUnsafeCall());
+         // As above, we only want to inline the JNI methods, so add an explicit test for isNative()
+         if (!methodSymbol->isNative())
+            break;
+
          if (TR::Compiler->target.is64Bit() && (node->isUnsafeGetPutCASCallOnNonArray() || !TR::Compiler->om.canGenerateArraylets()) && node->isSafeForCGToFastPathUnsafeCall())
             {
             resultReg = VMinlineCompareAndSwap(node, cg, true);
@@ -12896,6 +12906,10 @@ J9::Power::CodeGenerator::inlineDirectCall(TR::Node *node, TR::Register *&result
          break;
 
       case TR::sun_misc_Unsafe_compareAndSwapObject_jlObjectJjlObjectjlObject_Z:
+         // As above, we only want to inline the JNI methods, so add an explicit test for isNative()
+         if (!methodSymbol->isNative())
+            break;
+
          if ((node->isUnsafeGetPutCASCallOnNonArray() || !TR::Compiler->om.canGenerateArraylets()) && node->isSafeForCGToFastPathUnsafeCall())
             {
             resultReg = VMinlineCompareAndSwapObject(node, cg);