Nested String.concat making javac to crash with SOE.
Issue observed only on 9
==
-sh-4.1$ /opt/java/jdk-9_ea-95/bin/javac CompilerIssue.java


The system is out of resources.
Consult the following stack trace for details.
java.lang.StackOverflowError
        at com.sun.tools.javac.tree.TreeCopier.copy(TreeCopier.java:71)
        at com.sun.tools.javac.tree.TreeCopier.visitNewClass(TreeCopier.java:314)
        at com.sun.tools.javac.comp.DeferredAttr$2.visitNewClass(DeferredAttr.java:145)
        at com.sun.tools.javac.comp.DeferredAttr$2.visitNewClass(DeferredAttr.java:133)
        at com.sun.tools.javac.tree.JCTree$JCNewClass.accept(JCTree.java:1675)
        at com.sun.tools.javac.tree.TreeCopier.copy(TreeCopier.java:60)
        at com.sun.tools.javac.tree.TreeCopier.visitMemberSelect(TreeCopier.java:346)
        at com.sun.tools.javac.tree.TreeCopier.visitMemberSelect(TreeCopier.java:44)
        at com.sun.tools.javac.tree.JCTree$JCFieldAccess.accept(JCTree.java:2077)
        at com.sun.tools.javac.tree.TreeCopier.copy(TreeCopier.java:60)
        at com.sun.tools.javac.tree.TreeCopier.visitMethodInvocation(TreeCopier.java:289)
...