8357370: Export supported GCs in JVMCI

Reviewed-by: dnsimon

Author: rkennke

src/hotspot/share/jvmci/vmStructs_jvmci.cpp

@@ -496,6 +496,12 @@
 #define VM_INT_CONSTANTS(declare_constant, declare_constant_with_value, declare_preprocessor_constant) \
   declare_preprocessor_constant("ASSERT", DEBUG_ONLY(1) NOT_DEBUG(0))     \
                                                                           \
+  declare_preprocessor_constant("INCLUDE_SERIALGC", INCLUDE_SERIALGC)     \
+  declare_preprocessor_constant("INCLUDE_PARALLELGC", INCLUDE_PARALLELGC) \
+  declare_preprocessor_constant("INCLUDE_G1GC", INCLUDE_G1GC)             \
+  declare_preprocessor_constant("INCLUDE_ZGC", INCLUDE_ZGC)               \
+  declare_preprocessor_constant("INCLUDE_SHENANDOAHGC", INCLUDE_SHENANDOAHGC) \
+                                                                          \
   declare_constant(CompLevel_none)                                        \
   declare_constant(CompLevel_simple)                                      \
   declare_constant(CompLevel_limited_profile)                             \