Add the RSC instruction to the ARM integrated assembler.

src/DartARM32/assembler_arm.h

Index: src/DartARM32/assembler_arm.h
diff --git a/src/DartARM32/assembler_arm.h b/src/DartARM32/assembler_arm.h
index c0d224ea1627ce880d21340a051fae40d3bb35ad..00982b127ce912ab32efcee5f86ed9ec0dfc085a 100644
--- a/src/DartARM32/assembler_arm.h
+++ b/src/DartARM32/assembler_arm.h
@@ -473,15 +473,16 @@ class Assembler : public ValueObject {
   void adc(Register rd, Register rn, Operand o, Condition cond = AL);
 
   void adcs(Register rd, Register rn, Operand o, Condition cond = AL);
-#endif
 
+  // Moved to ARM32::AssemblerARM32::sbc()
   void sbc(Register rd, Register rn, Operand o, Condition cond = AL);
 
+  // Moved to ARM32::AssemblerARM32::sbc()
   void sbcs(Register rd, Register rn, Operand o, Condition cond = AL);
 
+  // Moved to ARM32::AssemblerARM32::rsc()
   void rsc(Register rd, Register rn, Operand o, Condition cond = AL);
 
-#if 0
   // Moved to ARM32::AssemblerARM32::tst();
   void tst(Register rn, Operand o, Condition cond = AL);
 #endif