Remove copy propagation from the native/WASM and Rust pipelines (#2846)

* Closes #2845 
* Copy propagation is not correct without subsequent adjusting of live
variables. See the comments in #2845.
* Enables JuvixReg transformations in the test suite, which exposes the
bug.
* Adds a test in JuvixAsm crafted specifically to expose this bug.

src/Juvix/Compiler/Pipeline.hs

@@ -378,5 +378,6 @@ asmToMiniC' = mapError (JuvixError @Asm.AsmError) . Asm.toReg' >=> regToMiniC' .
 
 regToMiniC' :: (Member (Reader Asm.Options) r) => Reg.InfoTable -> Sem r C.MiniCResult
 regToMiniC' tab = do
+  tab' <- Reg.toC tab
   e <- ask
-  return $ C.fromReg (e ^. Asm.optLimits) tab
+  return $ C.fromReg (e ^. Asm.optLimits) tab'

src/Juvix/Compiler/Reg/Data/TransformationId.hs

@@ -20,13 +20,11 @@ data PipelineId
 
 type TransformationLikeId = TransformationLikeId' TransformationId PipelineId
 
--- Note: this works only because for now we mark all variables as live. Liveness
--- information needs to be re-computed after copy propagation.
 toCTransformations :: [TransformationId]
-toCTransformations = [Cleanup, CopyPropagation]
+toCTransformations = [Cleanup]
 
 toRustTransformations :: [TransformationId]
-toRustTransformations = [Cleanup, CopyPropagation]
+toRustTransformations = [Cleanup]
 
 toCasmTransformations :: [TransformationId]
 toCasmTransformations = [Cleanup, CopyPropagation, SSA]

test/Asm/Run/Positive.hs

@@ -224,5 +224,10 @@ tests =
       "Test038: Apply & argsnum"
       $(mkRelDir ".")
       $(mkRelFile "test038.jva")
-      $(mkRelFile "out/test038.out")
+      $(mkRelFile "out/test038.out"),
+    PosTest
+      "Test039: Copy propagation"
+      $(mkRelDir ".")
+      $(mkRelFile "test039.jva")
+      $(mkRelFile "out/test039.out")
   ]

tests/Asm/positive/out/test039.out

@@ -0,0 +1 @@
+11

tests/Asm/positive/test039.jva

@@ -0,0 +1,42 @@
+-- Copy propagation
+
+-- This test will fail with the native/WASM backend if copy propagation is
+-- performed on JuvixReg without adjusting the live variables.
+
+function f(integer) {
+    push arg[0];
+    push 0;
+    eq;
+    br {
+        true: {
+            push 3;
+            push 4;
+            tsave {
+                tsave {
+                    push tmp[1];
+                    call f;
+                    push tmp[0];
+                    add;
+                    ret;
+                };
+            };
+        };
+        false: {
+            push arg[0];
+            push arg[0];
+            push arg[0];
+            push arg[0];
+            add;
+            sub;
+            add;
+            push 1;
+            add;
+            ret;
+        };
+    };
+}
+
+function main() {
+    push 0;
+    tcall f;
+}