selftest: remove "Yoda ordering" in assertions
gcc/ChangeLog:
* selftest.c (assert_streq): Rename "expected" and "actual" to
"val1" and "val2". Extend NULL-handling to cover both inputs
symmetrically, while still requiring both to be non-NULL for a pass.
* selftest.h (assert_streq): Rename "expected" and "actual" to
"val1" and "val2".
(ASSERT_EQ): Likewise.
(ASSERT_EQ_AT): Likewise.
(ASSERT_KNOWN_EQ): Likewise.
(ASSERT_KNOWN_EQ_AT): Likewise.
(ASSERT_NE): Likewise.
(ASSERT_MAYBE_NE): Likewise.
(ASSERT_MAYBE_NE_AT): Likewise.
(ASSERT_STREQ): Likewise. Clarify that both must be non-NULL for
the assertion to pass.
(ASSERT_STREQ_AT): Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@259782 138bc75d-0d04-0410-961f-82ee72b054a4