Implement DataView builtin

New API functions:
 - jerry_create_dataview
 - jerry_value_is_dataview
 - jerry_get_dataview_buffer
 - jerry_get_dataview_byte_offset
 - jerry_get_dataview_byte_length

JerryScript-DCO-1.0-Signed-off-by: Robert Fancsik frobert@inf.u-szeged.hu

Author: rerobika

docs/02.API-REFERENCE.md

@@ -63,6 +63,7 @@ Possible compile time enabled feature types:
  - JERRY_FEATURE_LINE_INFO - line info available
  - JERRY_FEATURE_LOGGING - logging
  - JERRY_FEATURE_SYMBOL - symbol support
+ - JERRY_FEATURE_DATAVIEW - DataView support
 
 ## jerry_regexp_flags_t
 
@@ -1296,6 +1297,56 @@ jerry_value_is_constructor (const jerry_value_t value)
 
 - [jerry_release_value](#jerry_release_value)
 
+## jerry_value_is_dataview
+
+**Summary**
+
+Returns whether the given `jerry_value_t` is a DataView object value.
+
+**Prototype**
+
+```c
+bool
+jerry_value_is_dataview (const jerry_value_t value)
+```
+
+- `value` - API value
+- return value
+  - true, if the given `jerry_value_t` is a DataView object
+  - false, otherwise
+
+**Example**
+
+[doctest]: # ()
+
+```c
+#include "jerryscript.h"
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t arraybuffer = jerry_create_arraybuffer (16);
+  jerry_value_t dataview = jerry_create_dataview (arraybuffer, 0, 16);
+
+  if (jerry_value_is_dataview (dataview))
+  {
+    // usage of dataview
+  }
+
+  jerry_release_value (dataview);
+  jerry_release_value (arraybuffer);
+
+  jerry_cleanup ();
+}
+```
+
+**See also**
+
+- [jerry_release_value](#jerry_release_value)
+
+
 ## jerry_value_is_error
 
 **Summary**
@@ -3246,6 +3297,60 @@ jerry_create_error_sz (jerry_error_t error_type,
 - [jerry_create_error](#jerry_create_error)
 
 
+## jerry_create_dataview
+
+**Summary**
+
+Create new JavaScript DataView object.
+
+*Note*: This API depends on the ES2015-subset profile.
+
+**Prototype**
+
+```c
+jerry_value_t
+jerry_create_dataview (const jerry_value_t array_buffer,
+                       const jerry_length_t byte_offset,
+                       const jerry_length_t byte_length)
+```
+
+- `array_buffer` - arrayBuffer to create DataView from
+- `byte_offset` - offset in bytes, to the first byte in the buffer
+- `byte_length` - number of elements in the byte array
+- return value
+  - value of the constructed DataView object - if success
+  - created error - otherwise
+
+**Example**
+
+[doctest]: # ()
+
+```c
+#include "jerryscript.h"
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t arraybuffer = jerry_create_arraybuffer (16);
+  jerry_value_t dataview = jerry_create_dataview (arraybuffer, 0, 16);
+
+  // usage of dataview
+
+  jerry_release_value (dataview);
+  jerry_release_value (arraybuffer);
+
+  jerry_cleanup ();
+}
+```
+
+**See also**
+
+- [jerry_value_is_dataview](#jerry_value_is_dataview)
+- [jerry_release_value](#jerry_release_value)
+
+
 ## jerry_create_external_function
 
 **Summary**
@@ -6120,6 +6225,152 @@ jerry_get_arraybuffer_pointer (const jerry_value_t value);
 - [jerry_create_arraybuffer_external](#jerry_create_arraybuffer_external)
 
 
+## jerry_get_dataview_buffer
+
+**Summary**
+
+Get the ArrayBuffer internal property of the DataView object.
+
+**Prototype**
+
+```c
+jerry_value_t
+jerry_get_dataview_buffer (const jerry_value_t value);
+```
+
+- `value` - DataView object.
+- return value
+  - the ArrayBuffer internal property - if success
+  - created error - otherwise
+
+**Example**
+
+[doctest]: # ()
+
+```c
+#include "jerryscript.h"
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t arraybuffer = jerry_create_arraybuffer (16);
+  jerry_value_t dataview = jerry_create_dataview (arraybuffer, 0, 16);
+  jerry_value_t internal_buffer = jerry_get_dataview_buffer (dataview);
+
+  // usage of internal_buffer
+
+  jerry_release_value (internal_buffer);
+  jerry_release_value (dataview);
+  jerry_release_value (arraybuffer);
+
+  jerry_cleanup ();
+}
+```
+
+**See also**
+
+- [jerry_create_dataview](#jerry_create_dataview)
+
+
+## jerry_get_dataview_byte_offset
+
+**Summary**
+
+Get the ByteOffset internal property of the DataView object.
+
+**Prototype**
+
+```c
+jerry_value_t
+jerry_get_dataview_byte_offset (const jerry_value_t value);
+```
+
+- `value` - DataView object.
+- return value
+  - the ByteOffset internal property - if success
+  - created error - otherwise
+
+**Example**
+
+[doctest]: # ()
+
+```c
+#include "jerryscript.h"
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t arraybuffer = jerry_create_arraybuffer (16);
+  jerry_value_t dataview = jerry_create_dataview (arraybuffer, 0, 16);
+  jerry_value_t byte_offset = jerry_get_dataview_byte_offset (dataview);
+
+  // usage of byte_offset
+
+  jerry_release_value (byte_offset);
+  jerry_release_value (dataview);
+  jerry_release_value (arraybuffer);
+
+  jerry_cleanup ();
+}
+```
+
+**See also**
+
+- [jerry_create_dataview](#jerry_create_dataview)
+
+## jerry_get_dataview_byte_offset
+
+**Summary**
+
+Get the ByteLength internal property of the DataView object.
+
+**Prototype**
+
+```c
+jerry_value_t
+jerry_get_dataview_byte_length (const jerry_value_t value);
+```
+
+- `value` - DataView object.
+- return value
+  - the ByteLength internal property - if success
+  - created error - otherwise
+
+**Example**
+
+[doctest]: # ()
+
+```c
+#include "jerryscript.h"
+
+int
+main (void)
+{
+  jerry_init (JERRY_INIT_EMPTY);
+
+  jerry_value_t arraybuffer = jerry_create_arraybuffer (16);
+  jerry_value_t dataview = jerry_create_dataview (arraybuffer, 0, 16);
+  jerry_value_t byte_length = jerry_get_dataview_byte_length (dataview);
+
+  // usage of byte_length
+
+  jerry_release_value (byte_length);
+  jerry_release_value (dataview);
+  jerry_release_value (arraybuffer);
+
+  jerry_cleanup ();
+}
+```
+
+**See also**
+
+- [jerry_create_dataview](#jerry_create_dataview)
+
+
 ## jerry_get_typedarray_type
 
 **Summary**