Fix problems with sandboxing and the ARM integrated assembler.

src/IceAssemblerARM32.h

Index: src/IceAssemblerARM32.h
diff --git a/src/IceAssemblerARM32.h b/src/IceAssemblerARM32.h
index 0ac8bc7359072e6a537705bfdf54a19dc9cc45cf..2bd7d3902aa43a0b569f56b31e501e1d37047061 100644
--- a/src/IceAssemblerARM32.h
+++ b/src/IceAssemblerARM32.h
@@ -135,10 +135,7 @@ public:
     return llvm::ArrayRef<uint8_t>(Padding, 4);
   }
 
-  void padWithNop(intptr_t Padding) override {
-    (void)Padding;
-    llvm_unreachable("Not yet implemented.");
-  }
+  void padWithNop(intptr_t Padding) override;
 
   Ice::Label *getCfgNodeLabel(SizeT NodeNumber) override {
     assert(NodeNumber < CfgNodeLabels.size());
@@ -239,6 +236,8 @@ public:
 
   void mvn(const Operand *OpRd, const Operand *OpScc, CondARM32::Cond Cond);
 
+  void nop();
+
   void orr(const Operand *OpRd, const Operand *OpRn, const Operand *OpSrc1,
            bool SetFlags, CondARM32::Cond Cond);