[gcc r12-7796] Properly reset the port handle when closing

[Eric Botcazou <ebotcazou@gcc.gnu.org>]

https://gcc.gnu.org/g:d937c6e44ba64694c0fc88f40f42390149d1d624

commit r12-7796-gd937c6e44ba64694c0fc88f40f42390149d1d624
Author: Pascal Obry <obry@adacore.com>
Date:   Thu Mar 24 11:30:05 2022 +0100

    Properly reset the port handle when closing
    
    When the serial port is closed, we need to ensure that the port handle is
    properly reset for it to be detected as closed.
    
    gcc/ada/
            PR ada/104767
            * libgnat/g-sercom__mingw.adb (Close): Reset port handle to -1.
            * libgnat/g-sercom__linux.adb (Close): Likewise.

Diff:
---
 gcc/ada/libgnat/g-sercom__linux.adb | 1 +
 gcc/ada/libgnat/g-sercom__mingw.adb | 1 +
 2 files changed, 2 insertions(+)

diff --git a/gcc/ada/libgnat/g-sercom__linux.adb b/gcc/ada/libgnat/g-sercom__linux.adb
index a2a64b1c17f..73bbb69300e 100644
--- a/gcc/ada/libgnat/g-sercom__linux.adb
+++ b/gcc/ada/libgnat/g-sercom__linux.adb
@@ -382,6 +382,7 @@ package body GNAT.Serial_Communications is
    begin
       if Port.H /= -1 then
          Res := close (int (Port.H));
+         Port.H := -1;
       end if;
    end Close;
 
diff --git a/gcc/ada/libgnat/g-sercom__mingw.adb b/gcc/ada/libgnat/g-sercom__mingw.adb
index aea78aead8c..d3301bd045b 100644
--- a/gcc/ada/libgnat/g-sercom__mingw.adb
+++ b/gcc/ada/libgnat/g-sercom__mingw.adb
@@ -70,6 +70,7 @@ package body GNAT.Serial_Communications is
    begin
       if Port.H /= -1 then
          Success := CloseHandle (HANDLE (Port.H));
+         Port.H := -1;
 
          if Success = Win32.FALSE then
             Raise_Error ("error closing the port");