[Driver] Remove elf::script indirection. NFC

There are 100+ references.
Use a wrapper similar to a623a4c

Author: MaskRay

lld/ELF/Driver.cpp

@@ -151,7 +151,7 @@ bool link(ArrayRef<const char *> args, llvm::raw_ostream &stdoutOS,
                                  "--error-limit=0 to see all errors)";
 
   config = ConfigWrapper();
-  script = std::make_unique<LinkerScript>();
+  script = ScriptWrapper();
 
   symAux.emplace_back();
 

lld/ELF/LinkerScript.cpp

@@ -44,7 +44,7 @@ using namespace llvm::support::endian;
 using namespace lld;
 using namespace lld::elf;
 
-std::unique_ptr<LinkerScript> elf::script;
+ScriptWrapper elf::script;
 
 static bool isSectionPrefix(StringRef prefix, StringRef name) {
   return name.consume_front(prefix) && (name.empty() || name[0] == '.');

lld/ELF/LinkerScript.h

@@ -402,7 +402,12 @@ class LinkerScript final {
   llvm::MapVector<StringRef, SmallVector<StringRef, 0>> provideMap;
 };
 
-LLVM_LIBRARY_VISIBILITY extern std::unique_ptr<LinkerScript> script;
+struct ScriptWrapper {
+  LinkerScript s;
+  LinkerScript *operator->() { return &s; }
+};
+
+LLVM_LIBRARY_VISIBILITY extern ScriptWrapper script;
 
 } // end namespace lld::elf