[llvm-c] Add UnaryOperator to LLVM_FOR_EACH_VALUE_SUBCLASS macro

Note that we are not sure where the tests for these functions lives. This was discussed in the Phab Diff.

Differential Revision: https://reviews.llvm.org/D68588

llvm-svn: 373969

llvm/include/llvm-c/Core.h

@@ -1543,6 +1543,7 @@ LLVMTypeRef LLVMX86MMXType(void);
           macro(GlobalVariable)             \
       macro(UndefValue)                     \
     macro(Instruction)                      \
+      macro(UnaryOperator)                  \
       macro(BinaryOperator)                 \
       macro(CallInst)                       \
         macro(IntrinsicInst)                \