[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.

(cherry picked from commit 45f538e)

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