Fix description of pointer in ldloca.s (#11314)

Apply #9574 to ldloca.s.

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Co-authored-by: Jan Kotas <jkotas@microsoft.com>

Author: Smaug123

xml/System.Reflection.Emit/OpCodes.xml

@@ -10422,7 +10422,7 @@ The following <xref:System.Reflection.Emit.ILGenerator.Emit%2A> method overloads
 
 1.  The address of the local variable at the specified index is pushed onto the stack.
 
- The `ldloca.s` 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.s` 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 `ldloca.s` instruction provides an efficient encoding for use with the local variables 0 through 255.