Move most wasmtime tests into one test suite (#1544)

* Move most wasmtime tests into one test suite

This commit moves most wasmtime tests into a single test suite which
gets compiled into one executable instead of having lots of test
executables. The goal here is to reduce disk space on CI, and this
should be achieved by having fewer executables which means fewer copies
of `libwasmtime.rlib` linked across binaries on the system. More
importantly though this means that DWARF debug information should only
be in one executable rather than duplicated across many.

* Share more build caches

Globally set `RUSTFLAGS` to `-Dwarnings` instead of individually so all
build steps share the same value.

* Allow some dead code in cranelift-codegen

Prevents having to fix all warnings for all possible feature
combinations, only the main ones which come up.

* Update some debug file paths

tests/all/wast.rs

@@ -0,0 +1,41 @@
+use std::path::Path;
+use wasmtime::{Config, Engine, OptLevel, Store, Strategy};
+use wasmtime_wast::WastContext;
+
+include!(concat!(env!("OUT_DIR"), "/wast_testsuite_tests.rs"));
+
+// Each of the tests included from `wast_testsuite_tests` will call this
+// function which actually executes the `wast` test suite given the `strategy`
+// to compile it.
+fn run_wast(wast: &str, strategy: Strategy) -> anyhow::Result<()> {
+    let wast = Path::new(wast);
+
+    let simd = wast.iter().any(|s| s == "simd");
+
+    let bulk_mem = wast.iter().any(|s| s == "bulk-memory-operations");
+
+    // Some simd tests assume support for multiple tables, which are introduced
+    // by reference types.
+    let reftypes = simd || wast.iter().any(|s| s == "reference-types");
+
+    let multi_val = wast.iter().any(|s| s == "multi-value");
+
+    let mut cfg = Config::new();
+    cfg.wasm_simd(simd)
+        .wasm_bulk_memory(bulk_mem)
+        .wasm_reference_types(reftypes)
+        .wasm_multi_value(multi_val)
+        .strategy(strategy)?
+        .cranelift_debug_verifier(true);
+
+    // FIXME: https://github.com/bytecodealliance/wasmtime/issues/1186
+    if simd {
+        cfg.cranelift_opt_level(OptLevel::None);
+    }
+
+    let store = Store::new(&Engine::new(&cfg));
+    let mut wast_context = WastContext::new(store);
+    wast_context.register_spectest()?;
+    wast_context.run_file(wast)?;
+    Ok(())
+}