Allow the embedder to pass the virtual memory limit to v8

src/spaces.cc

Index: src/spaces.cc
diff --git a/src/spaces.cc b/src/spaces.cc
index 59c17af1a682f895da807efe188584cb698e9507..dfa9cea71a73a1f895da56237c1107c0e819c08b 100644
--- a/src/spaces.cc
+++ b/src/spaces.cc
@@ -133,9 +133,19 @@ CodeRange::CodeRange(Isolate* isolate)
 }
 
 
-bool CodeRange::SetUp(const size_t requested) {
+bool CodeRange::SetUp(size_t requested) {
   ASSERT(code_range_ == NULL);
 
+  if (requested == 0) {
+    // On 64-bit platform(s), we put all code objects in a 512 MB range of
+    // virtual address space, so that they can call each other with near calls.
+    if (kIs64BitArch) {
+      requested = 512 * MB;
+    } else {
+      return true;
+    }
+  }
+
   code_range_ = new VirtualMemory(requested);
   CHECK(code_range_ != NULL);
   if (!code_range_->IsReserved()) {
@@ -146,7 +156,8 @@ bool CodeRange::SetUp(const size_t requested) {
 
   // We are sure that we have mapped a block of requested addresses.
   ASSERT(code_range_->size() == requested);
-  LOG(isolate_, NewEvent("CodeRange", code_range_->address(), requested));
+  LOG(isolate_,
+      NewEvent("CodeRange", code_range_->address(), requested));
   Address base = reinterpret_cast<Address>(code_range_->address());
   Address aligned_base =
       RoundUp(reinterpret_cast<Address>(code_range_->address()),