RFR(XS): JDK-8034176 Update mapfile for libjfr

[staffan]

Please review this small fix for libjfr/mapfile-vers.

Thanks,
/Staffan

diff --git a/make/mapfiles/libjfr/mapfile-vers 
b/make/mapfiles/libjfr/mapfile-vers
--- a/make/mapfiles/libjfr/mapfile-vers
+++ b/make/mapfiles/libjfr/mapfile-vers
@@ -34,6 +34,7 @@
       Java_oracle_jrockit_jfr_VMJFR_getPeriod;
       Java_oracle_jrockit_jfr_VMJFR_descriptors;
       Java_oracle_jrockit_jfr_VMJFR_redefineClass0;
+      Java_oracle_jrockit_jfr_VMJFR_retransformClasses0;
       JNI_OnLoad;
   local:
       *;