Revert the Metal Experiment (#701)

Metal sounded like a good idea to get in the emulator but frankly I
underestimated just how experimental and not ready it was.
From my write up in the Discord:
```
As is, Metal supports only a few games.
The games it does support freeze on first use of not playing them via Vulkan, because shader translation is broken.
So you need to use a dirty hack to not delete all your shaders.
Not to mention it breaks many games via MoltenVK because of changes to the shared GPU code.

Merging Metal seemed like a great idea, because of the few games it does support.
But I don't think it's worth it. Many of the games it breaks via MoltenVK *don't work via Metal*. 
Which effectively makes current Ryubing worse for Mac users than Ryujinx 1.1.1403.

I think what I'm gonna do is revert Metal, and reopen it as a PR. That way, you can still take advantage of the Metal backend as is, but without making other games worse with no solution.
```

For what it's worth, the shader translation part could at least be
"fixed" by always applying a 30ms delay for shader translation to Metal.
That being said, that solution sucks ass.
The MoltenVK regressions are even worse.



I hope this is not a let down to the Mac users. I hope you realize I'm
reverting this because you're actively getting a worse experience with
it in the emulator.

src/Ryujinx.Graphics.Shader/StructuredIr/HelperFunctionsMask.cs

@@ -7,14 +7,7 @@ namespace Ryujinx.Graphics.Shader.StructuredIr
     {
         MultiplyHighS32 = 1 << 2,
         MultiplyHighU32 = 1 << 3,
-
-        FindLSB = 1 << 5,
-        FindMSBS32 = 1 << 6,
-        FindMSBU32 = 1 << 7,
-
         SwizzleAdd = 1 << 10,
         FSI = 1 << 11,
-
-        Precise = 1 << 13
     }
 }

src/Ryujinx.Graphics.Shader/StructuredIr/StructuredProgram.cs

@@ -18,10 +18,9 @@ namespace Ryujinx.Graphics.Shader.StructuredIr
             ShaderDefinitions definitions,
             ResourceManager resourceManager,
             TargetLanguage targetLanguage,
-            bool precise,
             bool debugMode)
         {
-            StructuredProgramContext context = new(attributeUsage, definitions, resourceManager, precise, debugMode);
+            StructuredProgramContext context = new(attributeUsage, definitions, resourceManager, debugMode);
 
             for (int funcIndex = 0; funcIndex < functions.Count; funcIndex++)
             {
@@ -323,9 +322,8 @@ namespace Ryujinx.Graphics.Shader.StructuredIr
             }
 
             // Those instructions needs to be emulated by using helper functions,
-            // because they are NVIDIA specific or because the target language has
-            // no direct equivalent. Those flags helps the backend to decide which
-            // helper functions are needed on the final generated code.
+            // because they are NVIDIA specific. Those flags helps the backend to
+            // decide which helper functions are needed on the final generated code.
             switch (operation.Inst)
             {
                 case Instruction.MultiplyHighS32:
@@ -334,15 +332,6 @@ namespace Ryujinx.Graphics.Shader.StructuredIr
                 case Instruction.MultiplyHighU32:
                     context.Info.HelperFunctionsMask |= HelperFunctionsMask.MultiplyHighU32;
                     break;
-                case Instruction.FindLSB:
-                    context.Info.HelperFunctionsMask |= HelperFunctionsMask.FindLSB;
-                    break;
-                case Instruction.FindMSBS32:
-                    context.Info.HelperFunctionsMask |= HelperFunctionsMask.FindMSBS32;
-                    break;
-                case Instruction.FindMSBU32:
-                    context.Info.HelperFunctionsMask |= HelperFunctionsMask.FindMSBU32;
-                    break;
                 case Instruction.SwizzleAdd:
                     context.Info.HelperFunctionsMask |= HelperFunctionsMask.SwizzleAdd;
                     break;

src/Ryujinx.Graphics.Shader/StructuredIr/StructuredProgramContext.cs

@@ -36,10 +36,9 @@ namespace Ryujinx.Graphics.Shader.StructuredIr
             AttributeUsage attributeUsage,
             ShaderDefinitions definitions,
             ResourceManager resourceManager,
-            bool precise,
             bool debugMode)
         {
-            Info = new StructuredProgramInfo(precise);
+            Info = new StructuredProgramInfo();
 
             Definitions = definitions;
             ResourceManager = resourceManager;

src/Ryujinx.Graphics.Shader/StructuredIr/StructuredProgramInfo.cs

@@ -10,16 +10,11 @@ namespace Ryujinx.Graphics.Shader.StructuredIr
 
         public HelperFunctionsMask HelperFunctionsMask { get; set; }
 
-        public StructuredProgramInfo(bool precise)
+        public StructuredProgramInfo()
         {
-            Functions = [];
+            Functions = new List<StructuredFunction>();
 
-            IoDefinitions = [];
-
-            if (precise)
-            {
-                HelperFunctionsMask |= HelperFunctionsMask.Precise;
-            }
+            IoDefinitions = new HashSet<IoDefinition>();
         }
     }
 }