Make a pure function a non-member file-scoped function.

llvm-svn: 276524
diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 7c1a0ca..e140199 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -237,8 +237,7 @@
 // Reads and evaluates an arithmetic expression.
 uint64_t ExprParser::parseExpr() { return parseExpr1(parsePrimary(), 0); }
 
-template <class ELFT>
-bool LinkerScript<ELFT>::isDiscarded(InputSectionBase<ELFT> *S) {
+template <class ELFT> static bool isDiscarded(InputSectionBase<ELFT> *S) {
   return !S || !S->Live;
 }