Rework snapshot generation API. (#2259)

Also remove eval context support. It provides no practical advantage.

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

jerry-core/api/jerry-snapshot.h

@@ -33,11 +33,6 @@ typedef struct
   uint32_t func_offsets[1]; /**< function offsets (lowest bit: global(0) or eval(1) context) */
 } jerry_snapshot_header_t;
 
-/**
- * Evaluate this function on the top of the scope chain.
- */
-#define JERRY_SNAPSHOT_EVAL_CONTEXT 0x1u
-
 /**
  * Jerry snapshot magic marker.
  */
@@ -46,7 +41,7 @@ typedef struct
 /**
  * Jerry snapshot format version.
  */
-#define JERRY_SNAPSHOT_VERSION (10u)
+#define JERRY_SNAPSHOT_VERSION (11u)
 
 /**
  * Snapshot configuration flags.