Add PID to ALS log files

To avoid several ALS processes started at the same
time to write in the same log files.

For eng/ide/ada_language_server#1595

Author: AnthonyLeonardoGracio

doc/traces.md

@@ -10,7 +10,7 @@ Default traces configuration file names are:
    use the following contents as a starter:
 
    ```text
-   >ada_ls_log.$T.log:buffer_size=0
+   >ada_ls_log.$T.$$.log:buffer_size=0
    ALS.MAIN=yes
    ALS.IN=no
    ALS.OUT=no

source/ada/lsp-ada_driver.adb

@@ -413,7 +413,7 @@ begin
         & (if VSS.Command_Line.Is_Specified (Language_GPR_Option)
            then GPR_Log_File_Prefix
            else Ada_Log_File_Prefix)
-        & "_log.$T.log:buffer_size=0:buffer_size=0"
+        & "_log.$T.$$.log:buffer_size=0:buffer_size=0"
         & Ada.Characters.Latin_1.LF
         & "ALS.MAIN=yes"
         & Ada.Characters.Latin_1.LF

testsuite/.als/ada_ls_traces.cfg

@@ -1,4 +1,4 @@
->ada_ls_log.$T.log:buffer_size=0:buffer_size=0
+>ada_ls_log.$T.$$.log:buffer_size=0:buffer_size=0
 
 # Main trace
 ALS.MAIN=yes