Remove dependency from platform files on v8.h

src/platform-openbsd.cc

Index: src/platform-openbsd.cc
diff --git a/src/platform-openbsd.cc b/src/platform-openbsd.cc
index b09d588a3fcd23eda3a298304b82454685ee3b6b..c29ebde033d82685ba48e7b82fa033f43f39bd43 100644
--- a/src/platform-openbsd.cc
+++ b/src/platform-openbsd.cc
@@ -23,11 +23,12 @@
 #include <sys/types.h>  // mmap & munmap
 #include <unistd.h>     // sysconf
 
-#undef MAP_TYPE
+#include <cmath>
 
-#include "src/v8.h"
+#undef MAP_TYPE
 
 #include "src/platform.h"
+#include "src/utils.h"
 
 
 namespace v8 {
@@ -184,9 +185,9 @@ void OS::SignalCodeMovingGC() {
   // by the kernel and allows us to synchronize V8 code log and the
   // kernel log.
   int size = sysconf(_SC_PAGESIZE);
-  FILE* f = fopen(FLAG_gc_fake_mmap, "w+");
+  FILE* f = fopen(OS::GetGCFakeMMapFile(), "w+");
   if (f == NULL) {
-    OS::PrintError("Failed to open %s\n", FLAG_gc_fake_mmap);
+    OS::PrintError("Failed to open %s\n", OS::GetGCFakeMMapFile());
     OS::Abort();
   }
   void* addr = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_PRIVATE,
@@ -223,8 +224,8 @@ VirtualMemory::VirtualMemory(size_t size, size_t alignment)
                            kMmapFdOffset);
   if (reservation == MAP_FAILED) return;
 
-  Address base = static_cast<Address>(reservation);
-  Address aligned_base = RoundUp(base, alignment);
+  uint8_t* base = static_cast<uint8_t*>(reservation);
+  uint8_t* aligned_base = RoundUp(base, alignment);
   ASSERT_LE(base, aligned_base);
 
   // Unmap extra memory reserved before and after the desired block.