[DebugInfo] Fix instruction enumeration

These two opcodes were mistakenly swapped when they were originally
added, at least according to the `DebugInfo`, `OpenCL.DebugInfo.100`,
and `NonSemantic.Shader.DebugInfo.100` extended instruction sets.

This might break existing third-party SPIR-V translators if they are
accommodating this bug, mistakenly or otherwise.

lib/SPIRV/libSPIRV/SPIRV.debug.h

@@ -34,8 +34,8 @@ enum Instruction {
   TypePtrToMember               = 13,
   TypeTemplate                  = 14,
   TypeTemplateParameter         = 15,
-  TypeTemplateParameterPack     = 16,
-  TypeTemplateTemplateParameter = 17,
+  TypeTemplateTemplateParameter = 16,
+  TypeTemplateParameterPack     = 17,
   GlobalVariable                = 18,
   FunctionDeclaration           = 19,
   Function                      = 20,