added support for bitwise_lshift operation

include/xsimd/arch/xsimd_wasm.hpp

@@ -175,6 +175,33 @@ namespace xsimd
             return wasm_v128_or(self, other);
         }
 
+        // bitwise_lshift
+        template <class A, class T, class = typename std::enable_if<std::is_integral<T>::value, void>::type>
+        inline batch<T, A> bitwise_lshift(batch<T, A> const& self, int32_t other, requires_arch<wasm>) noexcept
+        {
+            XSIMD_IF_CONSTEXPR(sizeof(T) == 1)
+            {
+                return wasm_v128_and(wasm_i8x16_splat(0xFF << other), wasm_i32x4_shl(self, other));
+            }
+            else XSIMD_IF_CONSTEXPR(sizeof(T) == 2)
+            {
+                return wasm_i16x8_shl(self, other);
+            }
+            else XSIMD_IF_CONSTEXPR(sizeof(T) == 4)
+            {
+                return wasm_i32x4_shl(self, other);
+            }
+            else XSIMD_IF_CONSTEXPR(sizeof(T) == 8)
+            {
+                return wasm_i64x2_shl(self, other);
+            }
+            else
+            {
+                assert(false && "unsupported arch/op combination");
+                return {};
+            }
+        }
+
         // bitwise_xor
         template <class A, class T>
         inline batch<T, A> bitwise_xor(batch<T, A> const& self, batch<T, A> const& other, requires_arch<wasm>) noexcept