Add the concept of FloatRegister for all platforms.

src/s390/assembler-s390.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 72 matching lines @@
   V(r8)  V(r9)  V(r10) V(fp) V(ip) V(r13) V(r14) V(sp)
 
 #define ALLOCATABLE_GENERAL_REGISTERS(V)                  \
   V(r2)  V(r3)  V(r4)  V(r5)  V(r6)  V(r7)                \
   V(r8)  V(r9)  V(r13)
 
 #define DOUBLE_REGISTERS(V)                               \
   V(d0)  V(d1)  V(d2)  V(d3)  V(d4)  V(d5)  V(d6)  V(d7)  \
   V(d8)  V(d9)  V(d10) V(d11) V(d12) V(d13) V(d14) V(d15)
 
+#define FLOAT_REGISTERS DOUBLE_REGISTERS
+
 #define ALLOCATABLE_DOUBLE_REGISTERS(V)                   \
   V(d1)  V(d2)  V(d3)  V(d4)  V(d5)  V(d6)  V(d7)         \
   V(d8)  V(d9)  V(d10) V(d11) V(d12) V(d15) V(d0)
 // clang-format on
 
 // CPU Registers.
 //
 // 1) We would prefer to use an enum, but enum values are assignment-
 // compatible with int, which has caused code-generation bugs.
 //
@@ skipping 111 matching lines @@
   }
 
   static DoubleRegister from_code(int code) {
     DoubleRegister r = {code};
     return r;
   }
 
   int reg_code;
 };
 
-typedef DoubleRegister DoubleRegister;
+typedef DoubleRegister FloatRegister;
+
+// TODO(john.yan) Define SIMD registers.
+typedef DoubleRegister Simd128Register;
 
 #define DECLARE_REGISTER(R) \
   const DoubleRegister R = {DoubleRegister::kCode_##R};
 DOUBLE_REGISTERS(DECLARE_REGISTER)
 #undef DECLARE_REGISTER
 const Register no_dreg = {Register::kCode_no_reg};
 
 // Aliases for double registers.  Defined using #define instead of
 // "static const DoubleRegister&" because Clang complains otherwise when a
 // compilation unit that includes this header doesn't use the variables.
@@ skipping 23 matching lines @@
 
 const CRegister cr0 = {0};
 const CRegister cr1 = {1};
 const CRegister cr2 = {2};
 const CRegister cr3 = {3};
 const CRegister cr4 = {4};
 const CRegister cr5 = {5};
 const CRegister cr6 = {6};
 const CRegister cr7 = {7};
 
-// TODO(john.yan) Define SIMD registers.
-typedef DoubleRegister Simd128Register;
-
 // -----------------------------------------------------------------------------
 // Machine instruction Operands
 
 #if V8_TARGET_ARCH_S390X
 const RelocInfo::Mode kRelocInfo_NONEPTR = RelocInfo::NONE64;
 #else
 const RelocInfo::Mode kRelocInfo_NONEPTR = RelocInfo::NONE32;
 #endif
 
 // Class Operand represents a shifter operand in data processing instructions
@@ skipping 1176 matching lines @@
 
 class EnsureSpace BASE_EMBEDDED {
  public:
   explicit EnsureSpace(Assembler* assembler) { assembler->CheckBuffer(); }
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_S390_ASSEMBLER_S390_H_