8311285: report some fontconfig related environment variables in hs_err file

Reviewed-by: clanger, stuefe

src/hotspot/share/utilities/vmError.cpp

@@ -106,6 +106,8 @@ static const char* env_list[] = {
   "JAVA_HOME", "JAVA_TOOL_OPTIONS", "_JAVA_OPTIONS", "CLASSPATH",
   "PATH", "USERNAME",
 
+  "XDG_CACHE_HOME", "XDG_CONFIG_HOME", "FC_LANG", "FONTCONFIG_USE_MMAP",
+
   // Env variables that are defined on Linux/BSD
   "LD_LIBRARY_PATH", "LD_PRELOAD", "SHELL", "DISPLAY",
   "HOSTTYPE", "OSTYPE", "ARCH", "MACHTYPE",