RFR (M) 8146410: Interpreter functions are declared and defined in the wrong files

[Coleen Phillimore]

Summary: Moved functions to the correct files.

See bug for more details.

I basically did an hg mv templateInterpreter_<cpu>.cpp 
abstractInterpreter_<cpu>.cpp and moved the interpreter_<cpu>.cpp 
functions there.

Also moved generate_slow_signature_handler to 
TemplateInterpreterGenerator/CppInterpreterGenerator because it's not 
shared.

open webrev at http://cr.openjdk.java.net/~coleenp/8146410/
bug link https://bugs.openjdk.java.net/browse/JDK-8146410

Tested with JPRT on Oracle supported platforms and built zero on linux 
x86.  Also fixed change that broke zero in stack_zero.inline.hpp.  I 
think this should work on PPC and AARCH64, but please let me know.

One question for AARCH64 platform in file:

http://cr.openjdk.java.net/~coleenp/8146410/src/cpu/aarch64/vm/templateInterpreterGenerator_aarch64.cpp.udiff.html

thanks,
Coleen