Auto merge of #121265 - klensy:bump-18-02-24, r=Mark-Simulacrum

bump some deps

First commit dedupes darling* crates and remove one more syn 1.* dep
Second one bumps windows crate to 0.52

compiler/rustc_session/Cargo.toml

@@ -30,7 +30,7 @@ libc = "0.2"
 # tidy-alphabetical-end
 
 [target.'cfg(windows)'.dependencies.windows]
-version = "0.48.0"
+version = "0.52.0"
 features = [
     "Win32_Foundation",
     "Win32_System_LibraryLoader",

compiler/rustc_session/src/filesearch.rs

@@ -143,7 +143,6 @@ fn current_dll_path() -> Result<PathBuf, String> {
             &mut module,
         )
     }
-    .ok()
     .map_err(|e| e.to_string())?;
 
     let mut filename = vec![0; 1024];