Fix TLS support check for Darwin 32-bit simulator targets.

[vsapsai]

Summary

Also instead of checking architecture explicitly, use recently added
"simulator" environment in the triple.

rdar://problem/35083787

[arphaman]

LGTM, thanks

[vsapsai]

Thanks for prompt review.

clang/lib/Basic/Targets/OSTargets.h

DarwinTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
       : OSTargetInfo<Target>(Triple, Opts) {
     // By default, no TLS, and we whitelist permitted architecture/OS
     // combinations.
     this->TLSSupported = false;
 
     if (Triple.isMacOSX())
       this->TLSSupported = !Triple.isMacOSXVersionLT(10, 7);
     else if (Triple.isiOS()) {
-      // 64-bit iOS supported it from 8 onwards, 32-bit from 9 onwards.
-      if (Triple.getArch() == llvm::Triple::x86_64 ||
-          Triple.getArch() == llvm::Triple::aarch64)
+      // 64-bit iOS supported it from 8 onwards, 32-bit device from 9 onwards,
+      // 32-bit simulator from 10 onwards.
+      if (Triple.isArch64Bit())
         this->TLSSupported = !Triple.isOSVersionLT(8);
-      else if (Triple.getArch() == llvm::Triple::x86 ||
-               Triple.getArch() == llvm::Triple::arm ||
-               Triple.getArch() == llvm::Triple::thumb)
+      else if (Triple.isArch32Bit()) {
+        if (!Triple.isSimulatorEnvironment())
           this->TLSSupported = !Triple.isOSVersionLT(9);
-    } else if (Triple.isWatchOS())
+        else
+          this->TLSSupported = !Triple.isOSVersionLT(10);
+      }
+    } else if (Triple.isWatchOS()) {
+      if (!Triple.isSimulatorEnvironment())
         this->TLSSupported = !Triple.isOSVersionLT(2);
+      else
+        this->TLSSupported = !Triple.isOSVersionLT(3);
+    }
 
     this->MCountName = "\01mcount";
   }
 
   std::string isValidSectionSpecifier(StringRef SR) const override {
     // Let MCSectionMachO validate this.
     StringRef Segment, Section;
     unsigned TAA, StubSize;

clang/test/Sema/darwin-tls.c

 // RUN: not %clang_cc1 -fsyntax-only -triple x86_64-apple-macosx10.6 %s 2>&1 | FileCheck %s --check-prefix NO-TLS
 // RUN: %clang_cc1 -fsyntax-only -triple x86_64-apple-macosx10.7 %s 2>&1 | FileCheck %s --check-prefix TLS
+
 // RUN: not %clang_cc1 -fsyntax-only -triple arm64-apple-ios7.1 %s 2>&1 | FileCheck %s --check-prefix NO-TLS
 // RUN: %clang_cc1 -fsyntax-only -triple arm64-apple-ios8.0 %s 2>&1 | FileCheck %s --check-prefix TLS
 // RUN: not %clang_cc1 -fsyntax-only -triple thumbv7s-apple-ios8.3 %s 2>&1 | FileCheck %s --check-prefix NO-TLS
 // RUN: %clang_cc1 -fsyntax-only -triple thumbv7s-apple-ios9.0 %s 2>&1 | FileCheck %s --check-prefix TLS
 // RUN: %clang_cc1 -fsyntax-only -triple armv7-apple-ios9.0 %s 2>&1 | FileCheck %s --check-prefix TLS
+// RUN: not %clang_cc1 -fsyntax-only -triple i386-apple-ios9.0-simulator %s 2>&1 | FileCheck %s --check-prefix NO-TLS
+// RUN: %clang_cc1 -fsyntax-only -triple i386-apple-ios10.0-simulator %s 2>&1 | FileCheck %s --check-prefix TLS
+
 // RUN: not %clang_cc1 -fsyntax-only -triple thumbv7k-apple-watchos1.0 %s 2>&1 | FileCheck %s --check-prefix NO-TLS
 // RUN: %clang_cc1 -fsyntax-only -triple thumbv7k-apple-watchos2.0 %s 2>&1 | FileCheck %s --check-prefix TLS
+// RUN: not %clang_cc1 -fsyntax-only -triple i386-apple-watchos2.0-simulator %s 2>&1 | FileCheck %s --check-prefix NO-TLS
+// RUN: %clang_cc1 -fsyntax-only -triple i386-apple-watchos3.0-simulator %s 2>&1 | FileCheck %s --check-prefix TLS
 
 
 __thread int a;
 
 // NO-TLS: thread-local storage is not supported for the current target
 // TLS-NOT: thread-local storage is not supported for the current target
 
 wibble;