fix(build): Remove ambiguity in service method call (#327)

When calling methods on Arc<MyService> where the method is also defined on Arc (e.g. drop and clone), calling inner.#method_ident(request) will actually attempt to call the Arc method instead of the method on the service, resulting in a compile error. This change removes the ambiguity by dereferencing the inner Arc.

tests/ambiguous_methods/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "ambiguous_methods"
+version = "0.1.0"
+authors = ["Yonathan Randolph <[email protected]>"]
+edition = "2018"
+publish = false
+license = "MIT"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+tonic = { path= "../../tonic" }
+prost = "0.6"
+
+[build-dependencies]
+tonic-build = { path= "../../tonic-build" }