compiler: move wasm ABI workaround to transform package

By considering this as a regular transformation, it can be easily
tested.

transform/testdata/wasm-abi.ll

@@ -0,0 +1,28 @@
+target datalayout = "e-m:e-p:32:32-i64:64-n32:64-S128"
+target triple = "wasm32-unknown-unknown-wasm"
+
+declare i64 @externalCall(i8*, i32, i64)
+
+define internal i64 @testCall(i8* %ptr, i32 %len, i64 %foo) {
+  %val = call i64 @externalCall(i8* %ptr, i32 %len, i64 %foo)
+  ret i64 %val
+}
+
+define internal i64 @testCallNonEntry(i8* %ptr, i32 %len) {
+entry:
+  br label %bb1
+
+bb1:
+  %val = call i64 @externalCall(i8* %ptr, i32 %len, i64 3)
+  ret i64 %val
+}
+
+define void @exportedFunction(i64 %foo) {
+  %unused = shl i64 %foo, 1
+  ret void
+}
+
+define internal void @callExportedFunction(i64 %foo) {
+  call void @exportedFunction(i64 %foo)
+  ret void
+}