[WASM SIMD] Implement horizontal add for float and integer types.

src/arm/constants-arm.h

 // Copyright 2011 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_ARM_CONSTANTS_ARM_H_
 #define V8_ARM_CONSTANTS_ARM_H_
 
 #include <stdint.h>
 
 #include "src/base/logging.h"
@@ skipping 306 matching lines @@
   kBlockAddrModeMask = (8|4|1) << 21
 };
 
 
 // Coprocessor load/store operand size.
 enum LFlag {
   Long  = 1 << 22,  // Long load/store coprocessor.
   Short = 0 << 22   // Short load/store coprocessor.
 };
 
+// Neon sizes.
+enum NeonSize { Neon8 = 0x0, Neon16 = 0x1, Neon32 = 0x2, Neon64 = 0x3 };
 
 // NEON data type
 enum NeonDataType {
   NeonS8 = 0,
   NeonS16 = 1,
   NeonS32 = 2,
   // Gap to make it easier to extract U and size.
   NeonU8 = 4,
   NeonU16 = 5,
   NeonU32 = 6
 };
 
 inline int NeonU(NeonDataType dt) { return static_cast<int>(dt) >> 2; }
 inline int NeonSz(NeonDataType dt) { return static_cast<int>(dt) & 0x3; }
 
+// Convert sizes to data types (U bit is clear).
+inline NeonDataType NeonSizeToDatatype(NeonSize size) {
+  return static_cast<NeonDataType>(size);
+}
+
 enum NeonListType {
   nlt_1 = 0x7,
   nlt_2 = 0xA,
   nlt_3 = 0x6,
   nlt_4 = 0x2
 };
 
-enum NeonSize {
-  Neon8 = 0x0,
-  Neon16 = 0x1,
-  Neon32 = 0x2,
-  Neon64 = 0x3
-};
-
 // -----------------------------------------------------------------------------
 // Supervisor Call (svc) specific support.
 
 // Special Software Interrupt codes when used in the presence of the ARM
 // simulator.
 // svc (formerly swi) provides a 24bit immediate value. Use bits 22:0 for
 // standard SoftwareInterrupCode. Bit 23 is reserved for the stop feature.
 enum SoftwareInterruptCodes {
   // transition to C code
   kCallRtRedirected = 0x10,
@@ skipping 358 matching lines @@
 
  private:
   static const char* names_[kNumVFPRegisters];
 };
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ARM_CONSTANTS_ARM_H_