Add tests calling function imports.

crates/misc/dotnet/tests/Modules/FunctionThunking.wat

@@ -0,0 +1,20 @@
+(module
+ (type $FUNCSIG$iii (func (param i32 i32) (result i32)))
+ (type $FUNCSIG$v (func))
+ (import "env" "add" (func $add (param i32 i32) (result i32)))
+ (import "env" "do_throw" (func $do_throw))
+ (table 0 anyfunc)
+ (memory $0 1)
+ (export "memory" (memory $0))
+ (export "add_wrapper" (func $add_wrapper))
+ (export "do_throw_wrapper" (func $do_throw_wrapper))
+ (func $add_wrapper (; 2 ;) (param $0 i32) (param $1 i32) (result i32)
+  (call $add
+   (get_local $0)
+   (get_local $1)
+  )
+ )
+ (func $do_throw_wrapper (; 3 ;)
+  (call $do_throw)
+ )
+)