RFR (XXS) 8066292: Test java/nio/file/Files/CheckPermissions.java triggers stack overflow with -server -Xcomp

[Dean Long]

https://bugs.openjdk.java.net/browse/JDK-8066292

http://cr.openjdk.java.net/~dlong/8066292/webrev/

With -Xcomp, a cycle between compile requests and class loading can 
cause infinite recursion resulting in StackOverflowError's that are 
silently ignored.  To break the cycle, this changeset removes the 
ancient call to Method::load_signature_classes() for C2.  This call is 
no longer needed.

Tested in RBT with --test 
vm.compiler.testlist,hotspot/test/:hotspot_compiler_closed,hotspot/test/:hotspot_compiler_1,hotspot/test/:hotspot_compiler_2,hotspot/test/:hotspot_compiler_3

dl