* test/link: initial wasm support
This adds basic parsing and dumping of wasm section so they
can be tested using the new linker-test infrastructure.
* test/link: all wasm sections parsing and dumping
We now parse and dump all sections for the wasm binary format.
Currently, this only dumps the name of a custom section.
Later this should also dump symbol table, name, linking metadata and relocations.
All of those live within the custom sections.
* Add wasm linker test
This also fixes a parser mistake in reading the flags.
* test/link: implement linker tests wasm & fixes
Adds several test cases to test the wasm self-hosted linker.
This also introduces fixes that were caught during the implementation
of those tests.
* test-runner: obey omit_stage2 for standalone
When a standalone test requires stage2, but stage2 is omit
from the compiler, such test case will not be included as part
of the test suite that is being ran. This is to support CI's
where we omit stage2 to lower the memory usage.
