Updated old and added new IMG extensions. (KhronosGroup#90)

* Added IMG HTML extension files.

* Redirect previously published IMG extensions to their new HTML files.

* Added extension 66: cl_img_generate_mipmap.

* Added extension 67: cl_img_mem_properties.

* Updated clext.php with update IMG extensions.

* Alphabetise IMG extension ordering.

* Update txt versions of IMG extensions to signpost the HTML version.

extensions/clext.php

@@ -85,11 +85,11 @@
 </li>
 <li value=43><a href="extensions/intel/cl_intel_required_subgroup_size.html">cl_intel_required_subgroup_size</a>
 </li>
-<li value=44><a href="extensions/img/cl_img_cached_allocations.txt">cl_img_cached_allocations</a>
+<li value=44><a href="extensions/img/cl_img_cached_allocations.html">cl_img_cached_allocations</a>
 </li>
-<li value=45><a href="extensions/img/cl_img_use_gralloc_ptr.txt">cl_img_use_gralloc_ptr</a>
+<li value=45><a href="extensions/img/cl_img_use_gralloc_ptr.html">cl_img_use_gralloc_ptr</a>
 </li>
-<li value=46><a href="extensions/img/cl_img_yuv_image.txt">cl_img_yuv_image</a>
+<li value=46><a href="extensions/img/cl_img_yuv_image.html">cl_img_yuv_image</a>
 </li>
 <li value=47><a href="extensions/intel/cl_intel_driver_diagnostics.txt">cl_intel_driver_diagnostics</a>
 </li>
@@ -129,4 +129,8 @@
 </li>
 <li value=65><a href="extensions/intel/cl_intel_mem_force_host_memory.html">cl_intel_mem_force_host_memory</a>
 </li>
+<li value=66><a href="extensions/img/cl_img_generate_mipmap.html">cl_img_generate_mipmap</a>
+</li>
+<li value=67><a href="extensions/img/cl_img_mem_properties.html">cl_img_mem_properties</a>
+</li>
 </ol>

extensions/img/cl_img_cached_allocations.txt

@@ -1,96 +1,11 @@
-Name
+The cl_img_cached_allocations.txt extension is no longer authored in plain text.
 
-    IMG_cached_allocations
+Please refer to the HTML extension specification instead,
+which may be found here:
 
-Name Strings
+https://www.khronos.org/registry/OpenCL/extensions/img/cl_img_cached_allocations.html
 
-    cl_img_cached_allocations
+The asciidoc source for this extension specification may
+be found here:
 
-Contributors
-
-    Jeremy Kemp
-
-Contacts
-
-    Jeremy Kemp, Imagination Technologies (jeremy.kemp 'at' imgtec.com)
-
-Status
-
-    Unapproved.
-
-Version
-
-    Revision: #3, Nov 6, 2014
-
-Number
-
-    OpenCL Extension #44
-
-Dependencies
-
-    Requires OpenCL version 1.2 or later.
-
-    This extension is written against the wording of the OpenCL 1.2
-    Specification.
-
-Overview
-
-    This extension extends the functionality provided by
-    clCreateBuffer and clCreateImage to allow the OpenCL
-    implementation to allocate memory on the device which
-    is also cached on the host CPU.
-
-Glossary
-
-    None
-
-New Types
-
-    None
-
-New Procedures and Functions
-
-    None
-
-New Tokens
-
-    CL_MEM_USE_UNCACHED_CPU_MEMORY_IMG           (1 << 26)
-
-    CL_MEM_USE_CACHED_CPU_MEMORY_IMG           (1 << 27)
-
-Additions to Chapter 5 of the OpenCL 1.2 Specification (Memory Objects)
-
-    In Table 5.3, page 69, add the following text as a new row in the table:
-
-    "CL_MEM_USE_UNCACHED_CPU_MEMORY_IMG
-
-      If this flag is specified it means that the application wants the
-      OpenCL implementation to allocate memory on the device so that it
-      is not cached when accessed on the host."
-
-    In Table 5.3, page 69, add the following text as a new row in the table:
-
-    "CL_MEM_USE_CACHED_CPU_MEMORY_IMG
-
-      If this flag is specified it means that the application wants the
-      OpenCL implementation to allocate memory on the device so that it
-      is cached when accessed on the host."
-
-Issues
-
-    1.  This extension may or may not improve performance; it depends on the
-        specific use-case. It is most likely to improve performance in cases
-        where the buffer or image is mapped using clEnqueueMapBuffer/Image
-        and some processing is then performed on the host-side. Whether the
-        allocation flag improves performance depends on whether the overhead
-        of cache flushes is greater than the performance gain  from cached
-        memory accessing when doing the host-side processing. It's recommended
-        to apply the flag on case-by-case basis to see if it improves your
-        use-case.
-
-Revision History
-
-#2    - Update overview section to say that the extension also supports images.
-        Add more detail to the overview section.
-
-#1    - Initial revision.
+https://github.com/KhronosGroup/OpenCL-Docs/blob/master/extensions/cl_img_cached_allocations.asciidoc