[ELF] ICF: replace includeInDynsym with isExported

Similar to the change to MarkLive.cpp when isExported was introduced.
includeInDynsym might return true even when isExported is false for
statically linked executables.

Author: MaskRay

lld/ELF/Driver.cpp

@@ -2413,7 +2413,7 @@ static void findKeepUniqueSections(Ctx &ctx, opt::InputArgList &args) {
   // or DSOs, so we conservatively mark them as address-significant.
   bool icfSafe = ctx.arg.icf == ICFLevel::Safe;
   for (Symbol *sym : ctx.symtab->getSymbols())
-    if (sym->includeInDynsym(ctx))
+    if (sym->isExported)
       markAddrsig(icfSafe, sym);
 
   // Visit the address-significance table in each object file and mark each

lld/test/ELF/icf-safe.s

@@ -1,16 +1,19 @@
 # REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64 %S/Inputs/shared.s -o %ta.o
+# RUN: ld.lld -shared -soname=ta %ta.o -o %ta.so
 
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1.o
 # RUN: llvm-objcopy %t1.o %t1copy.o
 # RUN: llvm-objcopy --localize-symbol=h1 %t1.o %t1changed.o
 # RUN: ld.lld -r %t1.o -o %t1reloc.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %S/Inputs/icf-safe.s -o %t2.o
-# RUN: ld.lld %t1.o %t2.o -o %t2 --icf=safe --print-icf-sections | FileCheck %s
+# RUN: ld.lld %t1.o %t2.o -o %t2 --icf=safe --print-icf-sections --export-dynamic | FileCheck %s
 # RUN: ld.lld %t1copy.o %t2.o -o %t2 --icf=safe --print-icf-sections | FileCheck %s
 # RUN: ld.lld %t1.o %t2.o -o %t3 --icf=safe --print-icf-sections -shared | FileCheck --check-prefix=EXPORT %s
-# RUN: ld.lld %t1.o %t2.o -o %t3 --icf=safe --print-icf-sections --export-dynamic | FileCheck --check-prefix=EXPORT %s
+## Exported symbols are suppressed for ICF when dynamic linking is enabled.
+# RUN: ld.lld %t1.o %t2.o %ta.so -o %t3 --icf=safe --print-icf-sections --export-dynamic | FileCheck --check-prefix=EXPORT %s
 # RUN: ld.lld %t1.o %t2.o -o %t2 --icf=all --print-icf-sections | FileCheck --check-prefix=ALL %s
-# RUN: ld.lld %t1.o %t2.o -o %t2 --icf=all --print-icf-sections --export-dynamic | FileCheck --check-prefix=ALL-EXPORT %s
+# RUN: ld.lld %t1.o %t2.o %ta.so -o %t2 --icf=all --print-icf-sections --export-dynamic | FileCheck --check-prefix=ALL-EXPORT %s
 # RUN: ld.lld %t1changed.o -o %t4 --icf=safe 2>&1 | FileCheck --check-prefix=SH_LINK_0 %s
 # RUN: ld.lld %t1reloc.o -o %t4 --icf=safe 2>&1 | FileCheck --check-prefix=SH_LINK_0 %s