Factor out VM-independent part of DefaultHotSpotLoweringProvider into DefaultJavaLoweringProvider
Removed unused grow functionality on NodeMap.

--HG--
extra : rebase_source : 4eb8d90e0fbd6c506c7e37b544195c591d060f32
Truffle:  SourceManager renamed to SourceFactory
- All methods are static, no longer accessed via ExecutionContext
- Sources are indexed with weak references
- File content caching is now optional; off by default
Merge with f4510fd9e8b3ad6965b3162b27edb476baa7140d