merge revision(s) b8a3f1bd456f92866c4a7bd83235f78c574784a8:

	Fix crash in tracing object allocations

	ObjectSpace.trace_object_allocations_start could crash since it adds a
	TracePoint for when objects are freed. However, TracePoint could crash
	since it modifies st tables while inside the GC that is trying to free
	the object. This could cause a memory allocation to happen which would
	crash if it triggers another GC.

	See a crash log: http://ci.rvm.jp/results/trunk@ruby-sp1/4373707
	---
	 ext/objspace/depend           | 1 +
	 ext/objspace/object_tracing.c | 7 +++++++
	 gc.h                          | 4 ++--
	 3 files changed, 10 insertions(+), 2 deletions(-)

1 files changed, 2 insertions, 2 deletions

diff --git a/gc.h b/gc.h
index b2356444c6..23218c1a9e 100644
--- a/gc.h
+++ b/gc.h
@@ -116,8 +116,6 @@ int ruby_get_stack_grow_direction(volatile VALUE *addr);
 const char *rb_obj_info(VALUE obj);
 const char *rb_raw_obj_info(char *const buff, const size_t buff_size, VALUE obj);
 
-VALUE rb_gc_disable_no_rest(void);
-
 struct rb_thread_struct;
 
 size_t rb_size_pool_slot_size(unsigned char pool_id);
@@ -142,6 +140,8 @@ void rb_objspace_each_objects_without_setup(
 
 size_t rb_gc_obj_slot_size(VALUE obj);
 
+VALUE rb_gc_disable_no_rest(void);
+
 RUBY_SYMBOL_EXPORT_END
 
 #endif /* RUBY_GC_H */