RFR: Fix x86_32 builds and tests

[Aleksey Shipilev]

x86_32 is broken in sh/jdk, because it partially reverses the fixes we had in jdk/jdk. We need to
get them back like this:

diff -r b21a87c00c5d src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp
--- a/src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp   Thu Aug 15 20:10:59
2019 +0200
+++ b/src/hotspot/cpu/x86/gc/shenandoah/shenandoahBarrierSetAssembler_x86.cpp   Fri Aug 16 09:54:11
2019 +0200
@@ -855,10 +855,17 @@
   // Check for object being in the collection set.
   __ mov(tmp1, res);
   __ shrptr(tmp1, ShenandoahHeapRegion::region_size_bytes_shift_jint());
   __ movptr(tmp2, (intptr_t) ShenandoahHeap::in_cset_fast_test_addr());
+#ifdef _LP64
   __ movbool(tmp2, Address(tmp2, tmp1, Address::times_1));
   __ testbool(tmp2);
+#else
+  // On x86_32, C1 register allocator can give us the register without 8-bit support.
+  // Do the full-register access and test to avoid compilation failures.
+  __ movptr(tmp2, Address(tmp2, tmp1, Address::times_1));
+  __ testptr(tmp2, 0xFF);
+#endif
   __ jcc(Assembler::zero, *stub->continuation());

   __ bind(slow_path);
   ce->store_parameter(res, 0);
@@ -932,15 +939,23 @@
   __ prologue("shenandoah_load_reference_barrier", false);
   // arg0 : object to be resolved

   __ save_live_registers_no_oop_map(true);
+
+#ifdef _LP64
   __ load_parameter(0, c_rarg0);
   __ load_parameter(1, c_rarg1);
   if (UseCompressedOops) {
     __ call_VM_leaf(CAST_FROM_FN_PTR(address,
ShenandoahRuntime::load_reference_barrier_fixup_narrow), c_rarg0, c_rarg1);
   } else {
     __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_fixup),
c_rarg0, c_rarg1);
   }
+#else
+  __ load_parameter(0, rax);
+  __ load_parameter(1, rbx);
+  __ call_VM_leaf(CAST_FROM_FN_PTR(address, ShenandoahRuntime::load_reference_barrier_fixup), rax,
rbx);
+#endif
+
   __ restore_live_registers_except_rax(true);

   __ epilogue();
 }

Testing: {x86_32, x86_64} hotspot_gc_shenandoah

-- 
Thanks,
-Aleksey