Fix invalid pointer types in ldloca/ldarga descriptions (#9574)

Author: MichalPetryka

xml/System.Reflection.Emit/OpCodes.xml

@@ -6680,7 +6680,7 @@
 
 1.  The address `addr` of the argument indexed by `index` is pushed onto the stack.  
 
- The `ldarga` instruction fetches the address (of type `*`) of the argument indexed by `index`, where arguments are indexed from 0 onwards. The address `addr` is always aligned to a natural boundary on the target machine.  
+ The `ldarga` instruction fetches the address (of type `&`) of the argument indexed by `index`, where arguments are indexed from 0 onwards. The address `addr` is always aligned to a natural boundary on the target machine. The argument is stored in unmanaged memory, so the return value can be converted to an unmanaged pointer without pinning.
 
  For procedures that take a variable-length argument list, the `ldarga` instruction can be used only for the initial fixed arguments, not those in the variable part of the signature.  
 
@@ -10213,7 +10213,7 @@ The following <xref:System.Reflection.Emit.ILGenerator.Emit%2A> method overloads
 
 1.  The address stored in the local variable at the specified index is pushed onto the stack.  
 
- The `ldloca` instruction pushes the address of the local variable number at the passed index onto the stack, where local variables are numbered 0 onwards. The value pushed on the stack is already aligned correctly for use with instructions like <xref:System.Reflection.Emit.OpCodes.Ldind_I> and <xref:System.Reflection.Emit.OpCodes.Stind_I>. The result is a transient pointer (type `*`).  
+ The `ldloca` instruction pushes the address of the local variable number at the passed index onto the stack, where local variables are numbered 0 onwards. The value pushed on the stack is already aligned correctly for use with instructions like <xref:System.Reflection.Emit.OpCodes.Ldind_I> and <xref:System.Reflection.Emit.OpCodes.Stind_I>. The result is a managed pointer (type `&`). The local variable is stored in unmanaged memory, so the return value can be converted to an unmanaged pointer without pinning.
 
  The following <xref:System.Reflection.Emit.ILGenerator.Emit%2A> method overload can use the `ldloca` opcode: