RFR(S): 8202399:) [C1] LIRGenerator::do_CheckCast needs to exclude is_invokespecial_receiver_check() when using PatchAlot

[David Holmes]

Bug: https://bugs.openjdk.java.net/browse/JDK-8202399
webrev: http://cr.openjdk.java.net/~dholmes/8202399/webrev/

JDK-8168699 introduced  a special case for 
is_invokespecial_receiver_check() in LIRGenerator::do_CheckCast:

   } else if (x->is_invokespecial_receiver_check()) {
     assert(patching_info == NULL, "can't patch this");
     stub = new DeoptimizeStub(info_for_exception,
                               Deoptimization::Reason_class_check,
                               Deoptimization::Action_none);

but overlooked a potential bad interaction with PatchAlot. This can lead 
to  the assertion failure as observed during testing for JDK-8200167 
with Graal. The proposed fix (supplied by Vladimir) is quite simple but 
needs to be applied to each of the CPU specific files:

diff --git a/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp 
b/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
--- a/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
+++ b/src/hotspot/cpu/x86/c1_LIRGenerator_x86.cpp
@@ -1314,7 +1314,7 @@
     LIRItem obj(x->obj(), this);

     CodeEmitInfo* patching_info = NULL;
-  if (!x->klass()->is_loaded() || (PatchALot && 
!x->is_incompatible_class_change_check())) {
+  if (!x->klass()->is_loaded() || (PatchALot && 
!x->is_incompatible_class_change_check() && 
!x->is_invokespecial_receiver_check())) {

Testing:
  - hotspot/jtreg/compiler (complete)
  - hs-comp-precheckin (once mach5 is available)

Thanks,
David