Symbols defined in linker scripts should not have dso_local flag set in LTO resolutions

[dmikulin]

Summary

This is an extension to the fix in https://reviews.llvm.org/D42977

[dmikulin]

Changed the test to create linker script with "echo" instead.

ELF/LTO.cpp

R.VisibleToRegularObj = Config->Relocatable || Sym->IsUsedInRegularObj ||
                             (R.Prevailing && Sym->includeInDynsym()) ||
                             UsedStartStop.count(ObjSym.getSectionName());
     const auto *DR = dyn_cast<Defined>(Sym);
     R.FinalDefinitionInLinkageUnit =
         (IsExecutable || Sym->Visibility != STV_DEFAULT) && DR &&
         // Skip absolute symbols from ELF objects, otherwise PC-rel relocations
         // will be generated by for them, triggering linker errors.
         // Symbol section is always null for bitcode symbols, hence the check
-        // for isElf().
-        !(Sym->File && Sym->File->isElf() && DR->Section == nullptr);
+        // for isElf(). Skip linker script defined symbols as well: they have
+        // no File defined.
+        !(DR->Section == nullptr && (!Sym->File || Sym->File->isElf()));
 
     if (R.Prevailing)
       undefine(Sym);
 
     // We tell LTO to not apply interprocedural optimization for wrapped
     // (with --wrap) symbols because otherwise LTO would inline them while
     // their values are still not final.
     R.LinkerRedefined = !Sym->CanInline;

test/ELF/lto/abs-resol.ll

 ; REQUIRES: x86
 
 ; RUN: llvm-as %s -o %t.o
 ; RUN: llvm-mc -triple=x86_64-pc-linux %p/Inputs/absolute.s -o %t2.o -filetype=obj
-; RUN: ld.lld %t.o %t2.o -o %t.out -pie
+; RUN: ld.lld %t.o %t2.o -o %t3.out -pie
+
+; RUN: echo "blah = 0xdeadfeef;" > %t.script
+; RUN: ld.lld %t.o -T%t.script -o %t4.out -pie
 
 target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
 
 @blah = external global i8, align 1
 
 define i8* @_start() {
  ret i8* @blah
 }