aotcompile: reimplement canPartition correctly

This could previously cause any use of llvmcall to crash during ji
generate or generate bad code. Now it uses the llvm attribute to specify
this correctly.

src/aotcompile.cpp

@@ -900,12 +900,9 @@ struct Partition {
     size_t weight;
 };
 
-static bool canPartition(const GlobalValue &G) {
-    if (auto F = dyn_cast<Function>(&G)) {
-        if (F->hasFnAttribute(Attribute::AlwaysInline))
-            return false;
-    }
-    return true;
+static bool canPartition(const Function &F)
+{
+    return !F.hasFnAttribute(Attribute::AlwaysInline);
 }
 
 static inline bool verify_partitioning(const SmallVectorImpl<Partition> &partitions, const Module &M, DenseMap<GlobalValue *, unsigned> &fvars, DenseMap<GlobalValue *, unsigned> &gvars) {
@@ -947,13 +944,6 @@ static inline bool verify_partitioning(const SmallVectorImpl<Partition> &partiti
             }
         } else {
             // Local global values are not partitioned
-            if (!canPartition(GV)) {
-                if (GVNames.count(GV.getName())) {
-                    bad = true;
-                    dbgs() << "Shouldn't have partitioned " << GV.getName() << ", but is in partition " << GVNames[GV.getName()] << "\n";
-                }
-                continue;
-            }
             if (!GVNames.count(GV.getName())) {
                 bad = true;
                 dbgs() << "Global " << GV << " not in any partition\n";
@@ -1042,8 +1032,6 @@ static SmallVector<Partition, 32> partitionModule(Module &M, unsigned threads) {
     for (auto &G : M.global_values()) {
         if (G.isDeclaration())
             continue;
-        if (!canPartition(G))
-            continue;
         // Currently ccallable global aliases have extern linkage, we only want to make the
         // internally linked functions/global variables extern+hidden
         if (G.hasLocalLinkage()) {
@@ -1052,7 +1040,8 @@ static SmallVector<Partition, 32> partitionModule(Module &M, unsigned threads) {
         }
         if (auto F = dyn_cast<Function>(&G)) {
             partitioner.make(&G, getFunctionWeight(*F).weight);
-        } else {
+        }
+        else {
             partitioner.make(&G, 1);
         }
     }
@@ -1380,6 +1369,12 @@ static void materializePreserved(Module &M, Partition &partition) {
             continue;
         if (Preserve.contains(&F))
             continue;
+        if (!canPartition(F)) {
+            F.setLinkage(GlobalValue::AvailableExternallyLinkage);
+            F.setVisibility(GlobalValue::HiddenVisibility);
+            F.setDSOLocal(true);
+            continue;
+        }
         F.deleteBody();
         F.setLinkage(GlobalValue::ExternalLinkage);
         F.setVisibility(GlobalValue::HiddenVisibility);