src/share/vm/c1/c1_Compiler.cpp

rev 10271 : 8147844: new method j.l.Runtime.onSpinWait() and the corresponding x86 hotspot instrinsic
Summary: adds c1 & c2 x86 intrinsics for j.l.Runtime.onSpinWait() that utilize the PAUSE instruction
Reviewed-by: iveresov, kvn, vlivanov
Contributed-by: Ivan Krylov <ivan@azul.com>, Yuri Gaevsky <ygaevsky@azul.com>

@@ -129,10 +129,13 @@
     if (UseCompressedOops && !VM_Version::supports_atomic_getset4()) return false;
 #else
     if (!VM_Version::supports_atomic_getset4()) return false;
 #endif
     break;
+  case vmIntrinsics::_onSpinWait:
+    if (!VM_Version::supports_on_spin_wait()) return false;
+    break;
   case vmIntrinsics::_arraycopy:
   case vmIntrinsics::_currentTimeMillis:
   case vmIntrinsics::_nanoTime:
   case vmIntrinsics::_Reference_get:
     // Use the intrinsic version of Reference.get() so that the value in