Allow __builtin_setjmp/__builtin_longjmp on ARM

The problems in the llvm target got fixed in r242481 and r242482.

Related to rdar://20544153, rdar://20660786

llvm-svn: 242489

clang/lib/Basic/Targets.cpp

@@ -4750,6 +4750,10 @@ public:
     if (RegNo == 1) return 1;
     return -1;
   }
+
+  bool hasSjLjLowering() const override {
+    return true;
+  }
 };
 
 bool ARMTargetInfo::setFPMath(StringRef Name) {