[Offload][NFC] Use a sensible order for APIGen

The order entries in the tablegen API files are iterated is not the order
they appear in the file. To avoid any issues with the order changing
in future, we now generate all definitions of a certain class before
class that can use them.

This is a NFC; the definitions don't actually change, just the order
they exist in in the OffloadAPI.h header.

Author: RossBrunton

offload/liboffload/API/Common.td

@@ -127,7 +127,7 @@ def : Struct {
 def : Typedef {
   let name = "ol_result_t";
   let desc = "Result type returned by all entry points.";
-  let value = "const ol_error_struct_t*";
+  let value = "const struct ol_error_struct_t*";
 }
 
 def : Macro {

offload/tools/offload-tblgen/APIGen.cpp

@@ -226,31 +226,23 @@ OL_APIEXPORT ol_result_t OL_APICALL {0}WithCodeLoc(
 void EmitOffloadAPI(const RecordKeeper &Records, raw_ostream &OS) {
   OS << GenericHeader;
   OS << FileHeader;
-  // Generate main API definitions
-  for (auto *R : Records.getAllDerivedDefinitions("APIObject")) {
-    if (R->isSubClassOf("Macro")) {
-      ProcessMacro(MacroRec{R}, OS);
-    } else if (R->isSubClassOf("Typedef")) {
-      ProcessTypedef(TypedefRec{R}, OS);
-    } else if (R->isSubClassOf("Handle")) {
-      ProcessHandle(HandleRec{R}, OS);
-    } else if (R->isSubClassOf("Function")) {
-      ProcessFunction(FunctionRec{R}, OS);
-    } else if (R->isSubClassOf("Enum")) {
-      ProcessEnum(EnumRec{R}, OS);
-    } else if (R->isSubClassOf("Struct")) {
-      ProcessStruct(StructRec{R}, OS);
-    } else if (R->isSubClassOf("FptrTypedef")) {
-      ProcessFptrTypedef(FptrTypedefRec{R}, OS);
-    }
-  }
 
-  // Generate auxiliary definitions (func param structs etc)
+  // Generate main API definitions
+  for (auto *R : Records.getAllDerivedDefinitions("Macro"))
+    ProcessMacro(MacroRec{R}, OS);
+  for (auto *R : Records.getAllDerivedDefinitions("Handle"))
+    ProcessHandle(HandleRec{R}, OS);
+  for (auto *R : Records.getAllDerivedDefinitions("Enum"))
+    ProcessEnum(EnumRec{R}, OS);
+  for (auto *R : Records.getAllDerivedDefinitions("Typedef"))
+    ProcessTypedef(TypedefRec{R}, OS);
+  for (auto *R : Records.getAllDerivedDefinitions("FptrTypedef"))
+    ProcessFptrTypedef(FptrTypedefRec{R}, OS);
+  for (auto *R : Records.getAllDerivedDefinitions("Struct"))
+    ProcessStruct(StructRec{R}, OS);
   for (auto *R : Records.getAllDerivedDefinitions("Function")) {
     ProcessFuncParamStruct(FunctionRec{R}, OS);
-  }
-
-  for (auto *R : Records.getAllDerivedDefinitions("Function")) {
+    ProcessFunction(FunctionRec{R}, OS);
     ProcessFuncWithCodeLocVariant(FunctionRec{R}, OS);
   }