refactor amazon host detection to use bool

Author: futurejones

lib/Driver/UnixToolChains.cpp

@@ -111,22 +111,23 @@ ToolChain::InvocationInfo toolchains::GenericUnix::constructInvocation(
   return II;
 }
 // Amazon Linux 2023 requires lld as the default linker.
-std::string toolchains::GenericUnix::getDefaultLinker() const {
-  if (getTriple().isOSLinux()) {
-    std::ifstream file("/etc/os-release");
-    std::string line;
-
-    while (std::getline(file, line)) {
-      if (line.substr(0, 12) == "PRETTY_NAME=") {
-        if (line.substr(12) == "\"Amazon Linux 2023\"") {
-          file.close();
-          return "lld";
+bool isAmazonLinux2023Host() {
+      std::ifstream file("/etc/os-release");
+      std::string line;
+
+      while (std::getline(file, line)) {
+        if (line.substr(0, 12) == "PRETTY_NAME=") {
+          if (line.substr(12) == "\"Amazon Linux 2023\"") {
+            file.close();
+            return true;
+          }
         }
       }
+      return false;
     }
-  }
 
-  if (getTriple().isAndroid())
+std::string toolchains::GenericUnix::getDefaultLinker() const {
+  if (getTriple().isAndroid() || isAmazonLinux2023Host())
     return "lld";
 
   switch (getTriple().getArch()) {