RFR: 8199219: Build failures after JDK-8195148

[Aleksey Shipilev]

x86_32 build fails with:

src/hotspot/cpu/x86/stubGenerator_x86_32.cpp:708:2: error: #endif without #if
 #endif // INCLUDE_ALL_GCS
  ^~~~~

Bug:
 https://bugs.openjdk.java.net/browse/JDK-8199219

JDK-8195148 (G1 barrier set collapsing) change removed #if INCLUDE_ALL_GCS from
stubGenerator_x86_32, but not in other arches:
 http://hg.openjdk.java.net/jdk/hs/rev/edb65305d3ac#l36.1

Reinstating it makes the x86_32 build pass:

diff -r 0b48f0aa79ec src/hotspot/cpu/x86/stubGenerator_x86_32.cpp
--- a/src/hotspot/cpu/x86/stubGenerator_x86_32.cpp	Tue Mar 06 22:08:30 2018 -0800
+++ b/src/hotspot/cpu/x86/stubGenerator_x86_32.cpp	Wed Mar 07 10:45:45 2018 +0100
@@ -678,6 +678,7 @@
     assert_different_registers(start, count);
     BarrierSet* bs = Universe::heap()->barrier_set();
     switch (bs->kind()) {
+#if INCLUDE_ALL_GCS	
       case BarrierSet::G1BarrierSet:
         // With G1, don't generate the call if we statically know that the target in uninitialized
         if (!uninitialized_target) {
@@ -727,6 +728,7 @@
     BarrierSet* bs = Universe::heap()->barrier_set();
     assert_different_registers(start, count);
     switch (bs->kind()) {
+#if INCLUDE_ALL_GCS	
       case BarrierSet::G1BarrierSet:
         {
           __ pusha();                      // push registers

Testing: x86_32 build

Thanks,
-Aleksey