[Driver][OpenMP] Add support to create jobs for unbundling actions.

Summary:
This patch adds the support to create jobs for the `OffloadBundlingAction` which will invoke the `clang-offload-bundler` tool to unbundle input files.

Unlike other actions, unbundling actions have multiple outputs. Therefore, this patch adds the required changes to have a variant of `Tool::ConstructJob` with multiple outputs. 

The way the naming of the results is implemented is also slightly modified so that the same action can use a different offloading prefix for each use by the different offloading actions. 

With this patch, it is possible to compile a functional OpenMP binary with offloading support, even with separate compilation.

Reviewers: echristo, tra, jlebar, ABataev, hfinkel

Subscribers: mkuron, whchung, mehdi_amini, cfe-commits, Hahnfeld, andreybokhanko, arpith-jacob, carlo.bertolli, caomhin

Differential Revision: https://reviews.llvm.org/D21857

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@285326 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/Driver/Tool.cpp b/lib/Driver/Tool.cpp
index 7142e822f1..cf227bee83 100644
--- a/lib/Driver/Tool.cpp
+++ b/lib/Driver/Tool.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Driver/Tool.h"
+#include "InputInfo.h"
 
 using namespace clang::driver;
 
@@ -21,3 +22,12 @@ Tool::Tool(const char *_Name, const char *_ShortName, const ToolChain &TC,
 
 Tool::~Tool() {
 }
+
+void Tool::ConstructJob(Compilation &C, const JobAction &JA,
+                        const InputInfoList &Outputs,
+                        const InputInfoList &Inputs,
+                        const llvm::opt::ArgList &TCArgs,
+                        const char *LinkingOutput) const {
+  assert(Outputs.size() == 1 && "Expected only one output by default!");
+  ConstructJob(C, JA, Outputs.front(), Inputs, TCArgs, LinkingOutput);
+};