Experimental continuation implementation

This project is created to experiment on continuation implementation. The first approach we are trying right now is to store stack frames in some heap memory space and restore when continuation happens.

test.c: Experiment setting base pointer rbp and satck pointer rsp to point to heap storage and restore it later

test_ocr.c: The prototype of one process split-phase execution

test_spmd_ocr.c: Prototype considering several processes and split- phase execution

test_send_ocr.c: Example including point-to-point communication using OCR (spmd, split-phase execution)

Segmentation faults could happen while using Context DB stack. Modify the OCR memory allocator to allocate 16-byte aligned memory blocks to work around this problem.

To enable guid labeling in OCR, modify the OCR configuration file, and replace PTR with LABELED.