softcall_lookupmethod missing in intrp

[Mikael Pahmp]

When compiling the snapshot from yesterday with engine set to intrp, the linker 
reports softcall_lookupmethod as missing. This method is called from 
kaffe/kaffevm/kaffe.def and used to be defined in kaffe/kaffevm/intrp/icode.h. The 
latter file now instead contains a define of  softcall_lookupinterfacemethod which is 
never used nor defined elsewhere in any jit. I guess intrp/icode.h should be corrected.

/Mikael