Use VLDR instead of VMOVs from GPR when a 64-bit double can't be encoded as a VMOV immediate.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 0bf28ae5c5fbdc89cfdcd280eb8245046a4d6d1c..9a3dcd886caa0d29f9c57f38c1ba8e7e839f3cb6 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -210,7 +210,8 @@ class RelocInfo BASE_EMBEDDED {
     // add more as needed
     // Pseudo-types
     NUMBER_OF_MODES,  // There are at most 15 modes with noncompact encoding.
-    NONE,  // never recorded
+    NONE32,  // never recorded 32-bit value
+    NONE64,  // never recorded 64-bit value
     LAST_CODE_ENUM = DEBUG_BREAK,
     LAST_GCED_ENUM = GLOBAL_PROPERTY_CELL,
     // Modes <= LAST_COMPACT_ENUM are guaranteed to have compact encoding.
@@ -221,9 +222,12 @@ class RelocInfo BASE_EMBEDDED {
 
   RelocInfo() {}
 
-  RelocInfo(byte* pc, Mode rmode, intptr_t data, Code* host)
+  explicit RelocInfo(byte* pc, Mode rmode, intptr_t data, Code* host)
       : pc_(pc), rmode_(rmode), data_(data), host_(host) {
   }
+  explicit RelocInfo(byte* pc, double data64)
+      : pc_(pc), rmode_(NONE64), data64_(data64), host_(NULL) {
+  }
 
   static inline bool IsConstructCall(Mode mode) {
     return mode == CONSTRUCT_CALL;
@@ -262,6 +266,9 @@ class RelocInfo BASE_EMBEDDED {
   static inline bool IsDebugBreakSlot(Mode mode) {
     return mode == DEBUG_BREAK_SLOT;
   }
+  static inline bool IsNone(Mode mode) {
+    return mode == NONE32 || mode == NONE64;
+  }
   static inline int ModeMask(Mode mode) { return 1 << mode; }
 
   // Accessors
@@ -269,6 +276,7 @@ class RelocInfo BASE_EMBEDDED {
   void set_pc(byte* pc) { pc_ = pc; }
   Mode rmode() const {  return rmode_; }
   intptr_t data() const { return data_; }
+  double data64() const { return data64_; }
   Code* host() const { return host_; }
 
   // Apply a relocation by delta bytes
@@ -366,7 +374,10 @@ class RelocInfo BASE_EMBEDDED {
   // comment).
   byte* pc_;
   Mode rmode_;
-  intptr_t data_;
+  union {
+    intptr_t data_;
+    double data64_;
+  };
   Code* host_;
 #ifdef V8_TARGET_ARCH_MIPS
   // Code and Embedded Object pointers in mips are stored split