Split getPhdrsIndices. NFC.

llvm-svn: 276717
diff --git a/lld/ELF/LinkerScript.h b/lld/ELF/LinkerScript.h
index ade95ce..c64e7f7 100644
--- a/lld/ELF/LinkerScript.h
+++ b/lld/ELF/LinkerScript.h
@@ -144,6 +144,7 @@
 
   int getSectionIndex(StringRef Name);
   std::vector<size_t> getPhdrIndices(StringRef SectionName);
+  size_t getPhdrIndex(StringRef PhdrName);
   void dispatchAssignment(SymbolAssignment *Cmd);
 
   uintX_t Dot;