Add MethodImplOptions.AggressiveOptimization and use it for tiering (…

…#20009)

Add MethodImplOptions.AggressiveOptimization and use it for tiering

Part of fix for https://github.com/dotnet/corefx/issues/32235
Workaround for https://github.com/dotnet/coreclr/issues/19751
- Added and set CORJIT_FLAG_AGGRESSIVE_OPT to indicate that a method is flagged with AggressiveOptimization
- For a method flagged with AggressiveOptimization, tiering uses a foreground tier 1 JIT on first call to the method, skipping the tier 0 JIT and call counting
- When tiering is disabled, a method flagged with AggressiveOptimization does not use r2r-pregenerated code
- R2r crossgen does not generate code for a method flagged with AggressiveOptimization

Signed-off-by: dotnet-bot <dotnet-bot@microsoft.com>

src/Common/src/CoreLib/System/Runtime/CompilerServices/MethodImplOptions.cs

@@ -16,6 +16,7 @@ public enum MethodImplOptions
         NoOptimization = 0x0040,
         PreserveSig = 0x0080,
         AggressiveInlining = 0x0100,
+        AggressiveOptimization = 0x0200,
         InternalCall = 0x1000
     }
 }