cranelift: Merge all run tests into runtests dir

[afonso360]

With this change we now reuse tests across multiple arches.

Duplicate tests were merged into the same file where possible.
Some legacy x86 tests were left in separate files due to incompatibilities with the rest of the test suite.

We need someone with access to a s390x machine to check which ones of these should be commented out.

[bjorn3]

We need someone with access to a s390x machine to check which ones of these should be commented out.

cc @uweigand

[uweigand]

On s390x, we currently do not support any SIMD or i128 operations, so all the simd-* and i128-* tests need to be commented out for now.

Also, the const.clif test case exposes a pre-existing endian bug with handling bool test case return values: those are written as integers of the same width by the trampoline, but are always read out as the Rust "bool" type. This happens to work on little-endian systems, but fails for any boolean type larger than 1 byte on big-endian systems. I was able to fix this using the following patch:

diff --git a/cranelift/filetests/src/function_runner.rs b/cranelift/filetests/src/function_runner.rs
index a41d5f286..e4dcfeff4 100644
--- a/cranelift/filetests/src/function_runner.rs
+++ b/cranelift/filetests/src/function_runner.rs
@@ -251,7 +251,13 @@ impl UnboxedValues {
             ir::types::I64 => DataValue::I64(ptr::read(p as *const i64)),
             ir::types::F32 => DataValue::F32(ptr::read(p as *const Ieee32)),
             ir::types::F64 => DataValue::F64(ptr::read(p as *const Ieee64)),
-            _ if ty.is_bool() => DataValue::B(ptr::read(p as *const bool)),
+            _ if ty.is_bool() => match ty.bytes() {
+                1 => DataValue::B(ptr::read(p as *const i8) != 0),
+                2 => DataValue::B(ptr::read(p as *const i16) != 0),
+                4 => DataValue::B(ptr::read(p as *const i32) != 0),
+                8 => DataValue::B(ptr::read(p as *const i64) != 0),
+                _ => unimplemented!(),
+            }
             _ if ty.is_vector() && ty.bytes() == 16 => {
                 DataValue::V128(ptr::read(p as *const [u8; 16]))
             }

[afonso360]

@uweigand Thank you for taking a look at this! I've disabled simd & i128 tests, and applied your patch.

[cfallin]

Sorry for the delay in reviewing this! LGTM.

The CI failure appears to be a flaky WASI test; I'll respawn.