Implemented the RoundInt64ToFloat32 TurboFan operator for x64, arm64, and mips64.

src/compiler/arm64/instruction-codes-arm64.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_ARM64_INSTRUCTION_CODES_ARM64_H_
 #define V8_COMPILER_ARM64_INSTRUCTION_CODES_ARM64_H_
 
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ skipping 90 matching lines @@
   V(Arm64Float64Sqrt)              \
   V(Arm64Float64RoundDown)         \
   V(Arm64Float64RoundTiesAway)     \
   V(Arm64Float64RoundTruncate)     \
   V(Arm64Float64RoundUp)           \
   V(Arm64Float32ToFloat64)         \
   V(Arm64Float64ToFloat32)         \
   V(Arm64Float64ToInt32)           \
   V(Arm64Float64ToUint32)          \
   V(Arm64Int32ToFloat64)           \
+  V(Arm64Int64ToFloat32)           \
   V(Arm64Int64ToFloat64)           \
   V(Arm64Uint32ToFloat64)          \
   V(Arm64Float64ExtractLowWord32)  \
   V(Arm64Float64ExtractHighWord32) \
   V(Arm64Float64InsertLowWord32)   \
   V(Arm64Float64InsertHighWord32)  \
   V(Arm64Float64MoveU64)           \
   V(Arm64U64MoveFloat64)           \
   V(Arm64LdrS)                     \
   V(Arm64StrS)                     \
@@ skipping 35 matching lines @@
   V(Operand2_R_UXTB)  /* %r0 UXTB (unsigned extend byte) */     \
   V(Operand2_R_UXTH)  /* %r0 UXTH (unsigned extend halfword) */ \
   V(Operand2_R_SXTB)  /* %r0 SXTB (signed extend byte) */       \
   V(Operand2_R_SXTH)  /* %r0 SXTH (signed extend halfword) */
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_ARM64_INSTRUCTION_CODES_ARM64_H_