* src/SDCC.y (type_specifier2, pointer),

* src/SDCC.y (type_specifier2, pointer),
* src/SDCCsymt.h,
* src/SDCCsymt.c (mergeSpec, checkSClass),
* support/Util/SDCCerr.c,
* support/Util/SDCCerr.h: Parse and validate the restrict keyword
* support/valdiag/valdiag.py: Allow test cases to specify
  required language standard
* support/valdiag/tests/restrict.c: New file to test restrict keyword
* support/valdiag/tests/tentdecl.c: Supress empty source file error

git-svn-id: https://sdcc.svn.sourceforge.net/svnroot/sdcc/trunk/sdcc@4531 4a8a32a2-be11-0410-ad9d-d568d2c75423