Rename test files

Author: d-kalinichenko

ocaml/testsuite/tests/typing-layouts-bits32/basics.ml

@@ -13,7 +13,7 @@
 (* This file contains typing tests for the layout [bits32].
 
    Runtime tests for the type [int32#] can be found in the
-   [unboxed_int32], [alloc], and [int32_u] tests in this
+   [unboxed_int32], [alloc], and [test_int32_u] tests in this
    directory.  The type [int32#] here is used as a convenient example of a
    concrete [bits32] type in some tests, but its behavior isn't the primary
    purpose of this test. *)

ocaml/testsuite/tests/typing-layouts-bits32/bits32_u.ml renamed to ocaml/testsuite/tests/typing-layouts-bits32/test_int32_u.ml

@@ -13,7 +13,7 @@
 (* This file contains typing tests for the layout [bits64].
 
    Runtime tests for the type [int64#] can be found in the
-   [unboxed_int64], [alloc], and [int64_u] tests in this
+   [unboxed_int64], [alloc], and [test_int64_u] tests in this
    directory.  The type [int64#] here is used as a convenient example of a
    concrete [bits64] type in some tests, but its behavior isn't the primary
    purpose of this test. *)

ocaml/testsuite/tests/typing-layouts-bits64/basics.ml

@@ -13,7 +13,7 @@
 (* This file contains typing tests for the layout [word].
 
    Runtime tests for the type [nativeint#] can be found in the
-   [unboxed_nativeint], [alloc], and [word_u] tests in this
+   [unboxed_nativeint], [alloc], and [test_nativeint_u] tests in this
    directory.  The type [nativeint#] here is used as a convenient example of a
    concrete [word] type in some tests, but its behavior isn't the primary
    purpose of this test. *)