[clang][NewPM] Fix split debug test

[leonardchan]

Summary

This contains the part of D62225 which fixes CodeGen/split-debug-single-file.c by not placing .dwo sections when using -enable-split-dwarf=split.

[chandlerc]

Code change LGTM, but again, let's update the test to check both ways.

cfe/trunk/lib/CodeGen/BackendUtil.cpp

case Backend_EmitLL:
     break;
 
   case Backend_EmitAssembly:
   case Backend_EmitMCNull:
   case Backend_EmitObj:
     NeedCodeGen = true;
     CodeGenPasses.add(
         createTargetTransformInfoWrapperPass(getTargetIRAnalysis()));
-    if (!CodeGenOpts.SplitDwarfFile.empty()) {
+    if (!CodeGenOpts.SplitDwarfFile.empty() &&
+        CodeGenOpts.getSplitDwarfMode() == CodeGenOptions::SplitFileFission) {
       DwoOS = openOutputFile(CodeGenOpts.SplitDwarfFile);
       if (!DwoOS)
         return;
     }
     if (!AddEmitPasses(CodeGenPasses, Action, *OS,
                        DwoOS ? &DwoOS->os() : nullptr))
       // FIXME: Should we handle this error differently?
       return;

cfe/trunk/test/CodeGen/split-debug-single-file.c

 // REQUIRES: x86-registered-target
 
 // Testing to ensure -enable-split-dwarf=single allows to place .dwo sections into regular output object.
 //  RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux \
-//  RUN:   -enable-split-dwarf=single -split-dwarf-file %t.o -emit-obj -o %t.o %s
+//  RUN:   -enable-split-dwarf=single -split-dwarf-file %t.o -emit-obj -o %t.o %s -fno-experimental-new-pass-manager
+//  RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=MODE-SINGLE %s
+//  RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux \
+//  RUN:   -enable-split-dwarf=single -split-dwarf-file %t.o -emit-obj -o %t.o %s -fexperimental-new-pass-manager
 //  RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=MODE-SINGLE %s
 //  MODE-SINGLE: .dwo
 
 // Testing to ensure -enable-split-dwarf=split does not place .dwo sections into regular output object.
 //  RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux \
-//  RUN:   -enable-split-dwarf=split -split-dwarf-file %t.o -emit-obj -o %t.o %s
+//  RUN:   -enable-split-dwarf=split -split-dwarf-file %t.o -emit-obj -o %t.o %s -fno-experimental-new-pass-manager
+//  RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=MODE-SPLIT %s
+//  RUN: %clang_cc1 -debug-info-kind=limited -triple x86_64-unknown-linux \
+//  RUN:   -enable-split-dwarf=split -split-dwarf-file %t.o -emit-obj -o %t.o %s -fexperimental-new-pass-manager
 //  RUN: llvm-readobj -S %t.o | FileCheck --check-prefix=MODE-SPLIT %s
 //  MODE-SPLIT-NOT: .dwo
 
 int main (void) {
   return 0;
 }