[sanitizer-coverage/libFuzzer] make the guards for trace-pc 32-bit; create one array of guards per function, instead of one guard per BB. reorganize the code so that trace-pc-guard does not create unneeded globals

llvm-svn: 282735
diff --git a/llvm/lib/Fuzzer/FuzzerTracePC.h b/llvm/lib/Fuzzer/FuzzerTracePC.h
index 0f2b6a8..3f4c783 100644
--- a/llvm/lib/Fuzzer/FuzzerTracePC.h
+++ b/llvm/lib/Fuzzer/FuzzerTracePC.h
@@ -19,8 +19,8 @@
 
 class TracePC {
  public:
-  void HandleTrace(uintptr_t *guard, uintptr_t PC);
-  void HandleInit(uintptr_t *start, uintptr_t *stop);
+  void HandleTrace(uint32_t *guard, uintptr_t PC);
+  void HandleInit(uint32_t *start, uint32_t *stop);
   void HandleCallerCallee(uintptr_t Caller, uintptr_t Callee);
   void HandleValueProfile(size_t Value) { ValueProfileMap.AddValue(Value); }
   size_t GetTotalPCCoverage() { return TotalPCCoverage; }
@@ -71,7 +71,7 @@
   }
 
   struct Module {
-    uintptr_t *Start, *Stop;
+    uint32_t *Start, *Stop;
   };
 
   Module Modules[4096];