Update SYCL_INTEL_bf16_conversion.asciidoc

Align the document with changes made in intel#4989

Author: AlexeySotkin

sycl/doc/extensions/Bf16Conversion/SYCL_INTEL_bf16_conversion.asciidoc

@@ -124,6 +124,9 @@ public:
   bfloat16(const bfloat16 &) = default;
   ~bfloat16() = default;
 
+  // Explicit initialization
+  static bfloat16 from_bits(const storage_t &a);
+
   // Explicit conversion functions
   static storage_t from_float(const float &a);
   static float to_float(const storage_t &a);
@@ -132,15 +135,16 @@ public:
   bfloat16(const float &a);
   bfloat16 &operator=(const float &a);
 
-  // Convert from bfloat16 to float
+  // Convert bfloat16 to floating-point types
   operator float() const;
+  operator sycl::half() const
 
-  // Get bfloat16 as uint16.
-  operator storage_t() const;
-
-  // Convert to bool type
+  // Convert bfloat16 to bool type
   explicit operator bool();
 
+  // Get bfloat16 as raw bits.
+  storage_t raw() const;
+
   friend bfloat16 operator-(bfloat16 &bf) { /* ... */ }
 
   // OP is: prefix ++, --
@@ -177,6 +181,9 @@ Table 1. Member functions of `bfloat16` class.
 |===
 | Member Function | Description
 
+| `static bfloat16 from_bits(const storage_t &a);`
+| Create `bfloat16` with the `value` equals to `a`.
+
 |  `static storage_t from_float(const float &a);`
 |  Explicitly convert from `float` to `bfloat16`.
 
@@ -192,13 +199,16 @@ Table 1. Member functions of `bfloat16` class.
 | `operator float() const;`
 |  Return `bfloat16` value converted to `float`.
 
-| `operator storage_t() const;`
-| Return `uint16_t` value, whose bits represent `bfloat16` value.
+| `operator sycl::half() const;`
+| Return `bfloat16` value converted to `sycl::half`.
 
 | `explicit operator bool() { /* ... */ }`
-| Convert `bfloat16` to `bool` type. Return `false` if the value equals to
+| Convert `bfloat16` to `bool` type. Return `false` if the `value` equals to
   zero, return `true` otherwise.
 
+| `storage_t raw() const`
+| Return raw bits representing the `bfloat16` value.
+
 | `friend bfloat16 operator-(bfloat16 &bf) { /* ... */ }`
 | Construct new instance of `bfloat16` class with negated value of the `bf`.
 
@@ -329,4 +339,7 @@ None.
                              Add operator overloadings +
                              Apply code review suggestions
 |3|2021-08-18|Alexey Sotkin |Remove `uint16_t` constructor
+|4|2021-12-30|Alexey Sotkin |Add methods to explicitly set/get the value
+                             with/as raw bits. +
+                             Add `operator sycl::half()`
 |========================================