Add LLVMPassManagerBuilderRef Extensions (#114)

* LLVMPassManagerBuilderRef Extensions

* coding style for PassManagerBuilderRef extensions

sources/LLVMSharp/Extensions/LLVMPassManagerBuilderRef.cs

@@ -2,7 +2,7 @@
 
 namespace LLVMSharp
 {
-    public partial struct LLVMPassManagerBuilderRef : IEquatable<LLVMPassManagerBuilderRef>
+    public unsafe partial struct LLVMPassManagerBuilderRef : IEquatable<LLVMPassManagerBuilderRef>, IDisposable
     {
         public static bool operator ==(LLVMPassManagerBuilderRef left, LLVMPassManagerBuilderRef right) => left.Pointer == right.Pointer;
 
@@ -13,5 +13,35 @@ public partial struct LLVMPassManagerBuilderRef : IEquatable<LLVMPassManagerBuil
         public bool Equals(LLVMPassManagerBuilderRef other) => Pointer == other.Pointer;
 
         public override int GetHashCode() => Pointer.GetHashCode();
+
+        public void Dispose()
+        {
+            if (Pointer != IntPtr.Zero)
+            {
+                LLVM.PassManagerBuilderDispose(this);
+                Pointer = IntPtr.Zero;
+            }
+        }
+
+        public void SetOptLevel(uint OptLevel) => LLVM.PassManagerBuilderSetOptLevel(this, OptLevel);
+
+        public void SetSizeLevel(uint SizeLevel) => LLVM.PassManagerBuilderSetSizeLevel(this, SizeLevel);
+
+        public void SetDisableUnitAtATime(int Value) => LLVM.PassManagerBuilderSetDisableUnitAtATime(this, Value);
+
+        public void SetDisableUnrollLoops(int Value) => LLVM.PassManagerBuilderSetDisableUnrollLoops(this, Value);
+
+        public void SetDisableSimplifyLibCalls(int Value) => LLVM.PassManagerBuilderSetDisableSimplifyLibCalls(this, Value);
+
+        public void UseInlinerWithThreshold(uint Threshold) => LLVM.PassManagerBuilderUseInlinerWithThreshold(this, Threshold);
+
+        public void PopulateFunctionPassManager(LLVMPassManagerRef PM) => LLVM.PassManagerBuilderPopulateFunctionPassManager(this, PM);
+
+        public void PopulateModulePassManager(LLVMPassManagerRef PM) => LLVM.PassManagerBuilderPopulateModulePassManager(this, PM);
+
+        public void PopulateLTOPassManager(LLVMPassManagerRef PM, int Internalize, int RunInliner)
+        {
+            LLVM.PassManagerBuilderPopulateLTOPassManager(this, PM, Internalize, RunInliner);
+        }
     }
 }