Move resowner from common JitContext to LLVM specific

Only the LLVM specific code uses it since resource owners were made
extensible in commit b8bff07daa. This is
new in v17, so backpatch there to keep the branches from diverging
just yet.

Author: Andreas Karlsson <andreas@proxel.se>
Discussion: https://www.postgresql.org/message-id/fd3a2a00-6605-4e30-a118-48418b478e6e@proxel.se

src/backend/jit/llvm/llvmjit.c

@@ -249,7 +249,7 @@ llvm_create_context(int jitFlags)
 	context->base.flags = jitFlags;
 
 	/* ensure cleanup */
-	context->base.resowner = CurrentResourceOwner;
+	context->resowner = CurrentResourceOwner;
 	ResourceOwnerRememberJIT(CurrentResourceOwner, context);
 
 	llvm_jit_context_in_use_count++;
@@ -323,8 +323,8 @@ llvm_release_context(JitContext *context)
 
 	llvm_leave_fatal_on_oom();
 
-	if (context->resowner)
-		ResourceOwnerForgetJIT(context->resowner, llvm_jit_context);
+	if (llvm_jit_context->resowner)
+		ResourceOwnerForgetJIT(llvm_jit_context->resowner, llvm_jit_context);
 }
 
 /*
@@ -1372,8 +1372,8 @@ llvm_error_message(LLVMErrorRef error)
 static void
 ResOwnerReleaseJitContext(Datum res)
 {
-	JitContext *context = (JitContext *) DatumGetPointer(res);
+	LLVMJitContext *context = (LLVMJitContext *) DatumGetPointer(res);
 
 	context->resowner = NULL;
-	jit_release_context(context);
+	jit_release_context(&context->base);
 }

src/include/jit/jit.h

@@ -59,8 +59,6 @@ typedef struct JitContext
 	/* see PGJIT_* above */
 	int			flags;
 
-	ResourceOwner resowner;
-
 	JitInstrumentation instr;
 } JitContext;
 

src/include/jit/llvmjit.h

@@ -39,6 +39,9 @@ typedef struct LLVMJitContext
 {
 	JitContext	base;
 
+	/* used to ensure cleanup of context */
+	ResourceOwner resowner;
+
 	/* number of modules created */
 	size_t		module_generation;