Cap CL_DEVICE_MAX_MEM_ALLOC_SIZE to SIZE_MAX (#1501)

* Fix enqueue_flags test to use correct barrier type.

Currently, enqueue_flags test uses CLK_LOCAL_MEM_FENCE.
Use CLK_GLOBAL_MEM_FENCE instead as all threads across work-groups
need to wait here.

* Add check for support for Read-Wrie images

Read-Write images have required OpenCL 2.x.
Read-Write image tests are already being skipped
for 1.x devices.
With OpenCL 3.0, read-write images being optional,
the tests should be run or skipped
depending on the implementation support.

Add a check to decide if Read-Write images are
supported or required to be supported depending
on OpenCL version and decide if the tests should
be run on skipped.

Fixes issue #894

* Fix formatting in case of Read-Write image checks.

Fix formatting in case of Read-write image checks.
Also, combine two ifs into one in case of
kerne_read_write tests

* Fix some more formatting for RW-image checks

Remove unnecessary spaces at various places.
Also, fix lengthy lines.

* Fix malloc-size calculation in test imagedim

unsigned char size is silently assumed to be 1
in imagedim test of test_basic.
Pass sizeof(type) in malloc size calculation.
Also, change loop variable from signed to unsigned.
Add checks for null pointer for malloced memory.

* Cap CL_DEVICE_MAX_MEM_ALLOC_SIZE to SIZE_MAX

Cap CL_DEVICE_MAX_MEM_ALLOC_SIZE to SIZE_MAX
when CL_DEVICE_GLOBAL_MEM_SIZE is capped with SIZE_MAX.
test_allocation caps the value of GLOBAL_MEM_SIZE to SIZE_MAX
if it exceeds the value of SIZE_MAX(value depends on platform bitness),
but doesn’t modify MAX_ALLOC_SIZE the same way.
Due to this MAX_ALLOC_SIZE becomes greater than GLOBAL_MEM_SIZE
and the test fails.

Modify MAX_MEM_ALLOC_SIZE as GLOBAL_MEM_SIZE when it exceeds SIZE_MAX

OpenCL-CTS #1022

test_conformance/images/clCopyImage/test_copy_1D.cpp

@@ -113,6 +113,7 @@ int test_copy_image_set_1D( cl_device_id device, cl_context context, cl_command_
 
     if (memSize > (cl_ulong)SIZE_MAX) {
         memSize = (cl_ulong)SIZE_MAX;
+        maxAllocSize = (cl_ulong)SIZE_MAX;
     }
 
     if( gTestSmallImages )