cgraph: add selftest::symbol_table_test
This patch adds a selftest fixture for overriding the "symtab" global,
so that selftests involving symtab nodes can be isolated from each
other: each selftest can have its own symbol_table instance.
In particular, this ensures that nodes can have a predictable "order"
and thus predictable dump names within selftests.
gcc/ChangeLog:
* cgraph.c: Include "selftest.h".
(saved_symtab): New variable.
(selftest::symbol_table_test::symbol_table_test): New ctor.
(selftest::symbol_table_test::~symbol_table_test): New dtor.
(selftest::test_symbol_table_test): New test.
(selftest::cgraph_c_tests): New.
* cgraph.h (saved_symtab): New decl.
(selftest::symbol_table_test): New class.
* selftest-run-tests.c (selftest::run_tests): Call
selftest::cgraph_c_tests.
* selftest.h (selftest::cgraph_c_tests): New decl.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@265915 138bc75d-0d04-0410-961f-82ee72b054a4