[Clang][NewPM] Don't bail out if the target machine is empty

This matches the behavior of the old pass manager. There are some
targets that don't have target machine at all (e.g. le32, spir) which
whose tests would never run with new pass manager. Similarly, we would
need to disable tests for targets that are disabled.

Differential Revision: https://reviews.llvm.org/D58374

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@360100 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/BackendUtil.cpp b/lib/CodeGen/BackendUtil.cpp
index a43ebe9..cd2a5f6 100644
--- a/lib/CodeGen/BackendUtil.cpp
+++ b/lib/CodeGen/BackendUtil.cpp
@@ -965,13 +965,15 @@
   TimeRegion Region(FrontendTimesIsEnabled ? &CodeGenerationTime : nullptr);
   setCommandLineOpts(CodeGenOpts);
 
-  // The new pass manager always makes a target machine available to passes
-  // during construction.
-  CreateTargetMachine(/*MustCreateTM*/ true);
-  if (!TM)
-    // This will already be diagnosed, just bail.
+  bool RequiresCodeGen = (Action != Backend_EmitNothing &&
+                          Action != Backend_EmitBC &&
+                          Action != Backend_EmitLL);
+  CreateTargetMachine(RequiresCodeGen);
+
+  if (RequiresCodeGen && !TM)
     return;
-  TheModule->setDataLayout(TM->createDataLayout());
+  if (TM)
+    TheModule->setDataLayout(TM->createDataLayout());
 
   Optional<PGOOptions> PGOOpt;
 
diff --git a/test/CodeGen/spir-half-type.cpp b/test/CodeGen/spir-half-type.cpp
index b60931f..5cdc38e 100644
--- a/test/CodeGen/spir-half-type.cpp
+++ b/test/CodeGen/spir-half-type.cpp
@@ -1,5 +1,7 @@
 // RUN: %clang_cc1 -O0 -triple spir -emit-llvm %s -o - | FileCheck %s
 // RUN: %clang_cc1 -O0 -triple spir64 -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -O0 -triple spir -fexperimental-new-pass-manager -emit-llvm %s -o - | FileCheck %s
+// RUN: %clang_cc1 -O0 -triple spir64 -fexperimental-new-pass-manager -emit-llvm %s -o - | FileCheck %s
 
 // This file tests that using the _Float16 type with the spir target will not
 // use the llvm intrinsics but instead will use the half arithmetic
diff --git a/test/Driver/le32-unknown-nacl.cpp b/test/Driver/le32-unknown-nacl.cpp
index 9bbcdec..95d7487 100644
--- a/test/Driver/le32-unknown-nacl.cpp
+++ b/test/Driver/le32-unknown-nacl.cpp
@@ -1,5 +1,6 @@
 // RUN: %clang -target le32-unknown-nacl -### %s -emit-llvm-only -c 2>&1 | FileCheck %s -check-prefix=ECHO
 // RUN: %clang -target le32-unknown-nacl %s -emit-llvm -S -c -o - | FileCheck %s
+// RUN: %clang -target le32-unknown-nacl -fexperimental-new-pass-manager %s -emit-llvm -S -c -o - | FileCheck %s
 // RUN: %clang -target le32-unknown-nacl %s -emit-llvm -S -c -pthread -o - | FileCheck %s -check-prefix=THREADS
 
 // ECHO: {{.*}} "-cc1" {{.*}}le32-unknown-nacl.c