[SYCL][Doc] Mention alignment checks in ABI policy (#2795)

Author: Alexander Batashev

sycl/doc/ABIPolicyGuide.md

@@ -87,10 +87,11 @@ There is a set of tests to help identifying ABI changes:
   Please, prefer updating the test files with the above command. The checker
   script automatically sorts symbols. This would allow developers to avoid
   large diffs and help maintainers identify the nature of ABI changes.
-* `test/abi/layout*` and `test/abi/symbol_size*` are a group of tests to check
-  the internal layout of some classes. The `layout*` tests check some of API
-  classes for layout changes, while `symbol_size` only checks `sizeof` for API
-  classes. Changing the class layout is a breaking change.
+* `test/abi/layout*` and `test/abi/symbol_size_alignment.cpp` are a group of 
+  tests to check the internal layout of some classes. The `layout*` tests check 
+  some of API classes for layout changes, while `symbol_size_alignment` only 
+  checks `sizeof` and `alignof` for API classes. Changing the class layout is a 
+  breaking change.
 
 ## Changing ABI