Fix warnings on Win64.

src/assembler.cc

Index: src/assembler.cc
diff --git a/src/assembler.cc b/src/assembler.cc
index 1620fef00ceb72f26d4b1e81d87890f80b921ba4..9c9ddcdda69e8c5f60e98964a50d9655cf2e0d46 100644
--- a/src/assembler.cc
+++ b/src/assembler.cc
@@ -174,14 +174,14 @@ void RelocInfoWriter::WriteTaggedPC(uint32_t pc_delta, int tag) {
 
 
 void RelocInfoWriter::WriteTaggedData(intptr_t data_delta, int tag) {
-  *--pos_ = data_delta << kPositionTypeTagBits | tag;
+  *--pos_ = static_cast<byte>(data_delta << kPositionTypeTagBits | tag);
 }
 
 
 void RelocInfoWriter::WriteExtraTag(int extra_tag, int top_tag) {
-  *--pos_ = top_tag << (kTagBits + kExtraTagBits) |
-            extra_tag << kTagBits |
-            kDefaultTag;
+  *--pos_ = static_cast<int>(top_tag << (kTagBits + kExtraTagBits) |
+                             extra_tag << kTagBits |
+                             kDefaultTag);
 }
 
 
@@ -196,7 +196,7 @@ void RelocInfoWriter::WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag) {
 void RelocInfoWriter::WriteExtraTaggedData(intptr_t data_delta, int top_tag) {
   WriteExtraTag(kDataJumpTag, top_tag);
   for (int i = 0; i < kIntptrSize; i++) {
-    *--pos_ = data_delta;
+    *--pos_ = static_cast<byte>(data_delta);
   // Signed right shift is arithmetic shift.  Tested in test-utils.cc.
     data_delta = data_delta >> kBitsPerByte;
   }
@@ -211,7 +211,7 @@ void RelocInfoWriter::Write(const RelocInfo* rinfo) {
   ASSERT(rinfo->pc() - last_pc_ >= 0);
   ASSERT(RelocInfo::NUMBER_OF_MODES < kMaxRelocModes);
   // Use unsigned delta-encoding for pc.
-  uint32_t pc_delta = rinfo->pc() - last_pc_;
+  uint32_t pc_delta = static_cast<uint32_t>(rinfo->pc() - last_pc_);
   RelocInfo::Mode rmode = rinfo->rmode();
 
   // The two most common modes are given small tags, and usually fit in a byte.