Added support for SEA IR.

- Modified makefile to take the existance of SEA_IR_ART
  file to mean "switch to sea ir mode".
- Switching SEA IR mode on leads to the new compiler being
  fed the fibonacci methods only, if they are used as input.
- Added partial support for the control flow subgraph of
  the SEA IR (instruction nodes and region nodes for
  conditional and unconditional branches).

Change-Id: I29020b8e2df5a00fde75715c3683cc25038589f4

Conflicts:
	src/compiler/driver/compiler_driver.cc
diff --git a/.gitignore b/.gitignore
index 5973a95..1cdfed9 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,4 @@
 USE_LLVM_COMPILER
+USE_PORTABLE_COMPILER
+SMALL_ART
+SEA_IR_ART