Remove more #include directives from util/util.h.

This time, it was also necessary to remove using declarations,
which meant adding "std::" to everything. I left std::string
alone for now, but added a couple of TODOs for it.

Change-Id: Idc45d6587be3ac3a2be1c9c941b4bad5b7a3fdb3
Reviewed-on: https://code-review.googlesource.com/5443
Reviewed-by: Paul Wankadia <[email protected]>
diff --git a/re2/fuzzing/re2_fuzzer.cc b/re2/fuzzing/re2_fuzzer.cc
index df2afee..6fd8699 100644
--- a/re2/fuzzing/re2_fuzzer.cc
+++ b/re2/fuzzing/re2_fuzzer.cc
@@ -12,7 +12,6 @@
 
 using re2::FLAGS_minloglevel;
 using re2::StringPiece;
-using std::map;
 using std::string;
 
 // NOT static, NOT signed.
@@ -24,7 +23,7 @@
     return;
 
   // Don't waste time fuzzing high-fanout programs.
-  map<int, int> histogram;
+  std::map<int, int> histogram;
   int fanout = re.ProgramFanout(&histogram);
   if (fanout > 10)
     return;