use thin lto (#475)

Cargo.toml

@@ -44,4 +44,4 @@ cc = { version = "1.2", features = ["parallel"] }
 
 [profile.release]
 panic = "abort"
-lto = true
+lto = "thin"

build.rs

@@ -80,7 +80,7 @@ fn main() {
     }
 
     if profile == "release" {
-        rdp_build.flag("-flto");
+        rdp_build.flag("-flto=thin");
     }
     rdp_build.compile("parallel-rdp");
 
@@ -158,7 +158,7 @@ fn main() {
         simd_build.file(std::env::temp_dir().join("bindgen").join("extern.c"));
         simd_build.include(".");
         if profile == "release" {
-            simd_build.flag("-flto");
+            simd_build.flag("-flto=thin");
         }
         simd_build.compile("simd");
     }