[DWARFLinker] Honor verbose flag for input verification

Fix an inconsistency between input and output verification in dsymutil.
Previously, output verification would be controlled by the verbose flag,
while input verification would unconditionally dump to stdout. Make
input and output verification behave the same by printing verification
error to stderr in verbose mode only.

(cherry picked from commit 9f8678b)

Author: JDevlieghere

llvm/lib/DWARFLinker/DWARFLinker.cpp

@@ -2837,8 +2837,9 @@ Error DWARFLinker::cloneModuleUnit(LinkContext &Context, RefModuleUnit &Unit,
 bool DWARFLinker::verify(const DWARFFile &File) {
   assert(File.Dwarf);
 
+  raw_ostream &os = Options.Verbose ? errs() : nulls();
   DIDumpOptions DumpOpts;
-  if (!File.Dwarf->verify(llvm::outs(), DumpOpts.noImplicitRecursion())) {
+  if (!File.Dwarf->verify(os, DumpOpts.noImplicitRecursion())) {
     reportWarning("input verification failed", File);
     return false;
   }

llvm/test/tools/dsymutil/X86/verify.test

@@ -16,7 +16,8 @@
 # RUN: dsymutil -verify-dwarf=input -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefix=QUIET-INPUT-FAIL
 # RUN: dsymutil -verify-dwarf=none -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=QUIET-SUCCESS
 # RUN: not dsymutil -verify-dwarf=bogus -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=BOGUS
-# RUN: not dsymutil -verify-dwarf=all -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=QUIET-OUTPUT-FAIL,QUIET-INPUT-FAIL,VERBOSE-INPUT-FAIL
+# RUN: not dsymutil -verify-dwarf=all -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=QUIET-OUTPUT-FAIL,QUIET-INPUT-FAIL
+# RUN: not dsymutil -verify-dwarf=all -verbose -oso-prepend-path=%p/../Inputs -y %s -o %t 2>&1 | FileCheck %s --check-prefixes=VERBOSE-INPUT-FAIL
 
 # VERBOSE-INPUT-FAIL-DAG: error: Abbreviation declaration contains multiple DW_AT_language attributes.
 # QUIET-INPUT-FAIL-DAG: warning: input verification failed