config.gcc: Add sh-*-symbianelf target.

config.gcc: Add sh-*-symbianelf target.

* config.gcc: Add sh-*-symbianelf target.
* config/sh/sh.c: Add new target macros:
  TARGET_ENCODE_SECTION_INFO, TARGET_STRIP_NAME_ENCODING,
  TARGET_CXX_IMPORT_EXPORT_CLASS.
  (sh_file_start): Create a definition of the .directive section.
  (sh_attribute): Add dllimport and dllexport attributes.
* config/sh/symbian-pre.h: New file.
* config/sh/symbian-post.h: New file.
* config/sh/symbian.c: New file. Contains Symbian specific functions.
* config/sh/sh-protos.h: Add prototypes for new functions provided by symbian.c.
* config/sh/t-symbian: New file.
* doc/extend.texi: Document support for dllimport and dllexport	attributes by
  the sh-symbianelf target.

From-SVN: r84551