Access to com.sun.jndi.ldap.pool.Pool.map isn't synchronized in several executing paths: in methods toString(), showStats() and getPooledConnection().

In particular, this results in ConcurrentModificationException when debug information is on.

Example of a stack trace with CME:
Caused By: java.util.ConcurrentModificationException
        at java.util.WeakHashMap$HashIterator.nextEntry(WeakHashMap.java:882)
        at java.util.WeakHashMap$EntryIterator.next(WeakHashMap.java:921)
        at java.util.WeakHashMap$EntryIterator.next(WeakHashMap.java:919)
        at java.util.AbstractMap.toString(AbstractMap.java:518)
        at com.sun.jndi.ldap.pool.Pool.toString(Pool.java:229)
        at java.lang.String.valueOf(String.java:2849)
        at java.lang.StringBuilder.append(StringBuilder.java:128)
        at com.sun.jndi.ldap.pool.Pool.d(Pool.java:240)
        at com.sun.jndi.ldap.pool.Pool.getPooledConnection(Pool.java:120)
        at
com.sun.jndi.ldap.LdapPoolManager.getLdapClient(LdapPoolManager.java:329)
        at com.sun.jndi.ldap.LdapClient.getInstance(LdapClient.java:1603)
        at com.sun.jndi.ldap.LdapCtx.connect(LdapCtx.java:2699)
        at com.sun.jndi.ldap.LdapCtx.<init>(LdapCtx.java:317)