fix 219156 support static malloc or alternate malloc lib (e.g. tcmalloc) with new...

fix 219156 support static malloc or alternate malloc lib (e.g. tcmalloc) with new option --soname-synonyms

* pub_tool_redir.h : define the prefix to be used for "soname synonym"
  place holder
* vg_replace_malloc.c : define synonym place holder for malloc related
  functions
* m_redir.c : when detecting a soname synonym place holder redir spec, search
  in clo_soname_synonyms if there is a synonym pattern.
  If yes, replace the soname pattern. If not, ignore the redir spec.
* various files: implement or document the new clo --soname-synonyms
* new test memcheck/tests/static_malloc.vgtest

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@12559