Reapply "[GlobalISel] Remove the GISelAccessor API."

This reverts commit r310425, thus reapplying r310335 with a fix for link
issue of the AArch64 unittests on Linux bots when BUILD_SHARED_LIBS is ON.

Original commit message:
[GlobalISel] Remove the GISelAccessor API.

Its sole purpose was to avoid spreading around ifdefs related to
building global-isel. Since r309990, GlobalISel is not optional anymore,
thus, we can get rid of this mechanism all together.

NFC.

----
The fix for the link issue consists in adding the GlobalISel library in
the list of dependencies for the AArch64 unittests. This dependency
comes from the use of AArch64Subtarget that needs to know how
to destruct the GISel related APIs when being detroyed.

Thanks to Bill Seurer and Ahmed Bougacha for helping me reproducing and
understand the problem.

llvm-svn: 310969

1 files changed, 8 insertions, 41 deletions

diff --git a/llvm/lib/Target/X86/X86Subtarget.cpp b/llvm/lib/Target/X86/X86Subtarget.cpp
index 1b02b88c187..a3a9929d242 100644
--- a/llvm/lib/Target/X86/X86Subtarget.cpp
+++ b/llvm/lib/Target/X86/X86Subtarget.cpp
@@ -369,33 +369,6 @@ X86Subtarget &X86Subtarget::initializeSubtargetDependencies(StringRef CPU,
   return *this;
 }
 
-namespace {
-
-struct X86GISelActualAccessor : public GISelAccessor {
-  std::unique_ptr<CallLowering> CallLoweringInfo;
-  std::unique_ptr<LegalizerInfo> Legalizer;
-  std::unique_ptr<RegisterBankInfo> RegBankInfo;
-  std::unique_ptr<InstructionSelector> InstSelector;
-
-  const CallLowering *getCallLowering() const override {
-    return CallLoweringInfo.get();
-  }
-
-  const InstructionSelector *getInstructionSelector() const override {
-    return InstSelector.get();
-  }
-
-  const LegalizerInfo *getLegalizerInfo() const override {
-    return Legalizer.get();
-  }
-
-  const RegisterBankInfo *getRegBankInfo() const override {
-    return RegBankInfo.get();
-  }
-};
-
-} // end anonymous namespace
-
 X86Subtarget::X86Subtarget(const Triple &TT, StringRef CPU, StringRef FS,
                            const X86TargetMachine &TM,
                            unsigned StackAlignOverride)
@@ -420,35 +393,29 @@ X86Subtarget::X86Subtarget(const Triple &TT, StringRef CPU, StringRef FS,
     setPICStyle(PICStyles::StubPIC);
   else if (isTargetELF())
     setPICStyle(PICStyles::GOT);
-  X86GISelActualAccessor *GISel = new X86GISelActualAccessor();
 
-  GISel->CallLoweringInfo.reset(new X86CallLowering(*getTargetLowering()));
-  GISel->Legalizer.reset(new X86LegalizerInfo(*this, TM));
+  CallLoweringInfo.reset(new X86CallLowering(*getTargetLowering()));
+  Legalizer.reset(new X86LegalizerInfo(*this, TM));
 
   auto *RBI = new X86RegisterBankInfo(*getRegisterInfo());
-  GISel->RegBankInfo.reset(RBI);
-  GISel->InstSelector.reset(createX86InstructionSelector(TM, *this, *RBI));
-  setGISelAccessor(*GISel);
+  RegBankInfo.reset(RBI);
+  InstSelector.reset(createX86InstructionSelector(TM, *this, *RBI));
 }
 
 const CallLowering *X86Subtarget::getCallLowering() const {
-  assert(GISel && "Access to GlobalISel APIs not set");
-  return GISel->getCallLowering();
+  return CallLoweringInfo.get();
 }
 
 const InstructionSelector *X86Subtarget::getInstructionSelector() const {
-  assert(GISel && "Access to GlobalISel APIs not set");
-  return GISel->getInstructionSelector();
+  return InstSelector.get();
 }
 
 const LegalizerInfo *X86Subtarget::getLegalizerInfo() const {
-  assert(GISel && "Access to GlobalISel APIs not set");
-  return GISel->getLegalizerInfo();
+  return Legalizer.get();
 }
 
 const RegisterBankInfo *X86Subtarget::getRegBankInfo() const {
-  assert(GISel && "Access to GlobalISel APIs not set");
-  return GISel->getRegBankInfo();
+  return RegBankInfo.get();
 }
 
 bool X86Subtarget::enableEarlyIfConversion() const {