Remapping of ARM64 to AARCH64

[mosteo]

As mentioned in #960

[wiremoons]

Hi @Fabien-Chouteau and @mosteo

Thank you for fixing this output on Apple Silicon hardware, as discussed in #960

As an update, I have just re-built alr on HEAD, and the output is as below.

% ./bin/alr version
APPLICATION                                                                                    
alr version:            1.2.0-dev                                                              
libalire version:       1.2.0-dev                                                              
compilation date:       2022-04-09 07:18:19                                                    
compiler version:       12.0.1 20220312 (experimental)                                         
                       
CONFIGURATION          
config folder:          /Users/simon/.config/alire                                             
force flag:             FALSE                                                                  
non-interactive flag:   FALSE                                                                  
community index branch: stable-1.1                                                             
indexes folder:         /Users/simon/.config/alire/indexes                                     
indexes metadata:       OK                                                                     
index #1:               (community) git+https://github.com/alire-project/alire-index#stable-1.1
toolchain assistant:    disabled                                                               
tool #1 gnat:           gnat_external=12.0.1                                                   
tool #2 gprbuild:       gprbuild=22.0.0                                                        
                       
WORKSPACE              
root status:            VALID                                                                  
root release:           alr=1.2.0-dev                                                          
root load error:        none                                                                   
root folder:            /Users/simon/scratch/ada/builds/alire                                  
current folder:         /Users/simon/scratch/ada/builds/alire                                  
                       
SYSTEM                 
distribution:           DISTRO_UNKNOWN                                                         
host-arch:              AARCH64                                                                
os:                     MACOS                                                                  
target:                 NATIVE                                                                 
toolchain:              USER                                                                   
word-size:              BITS_64 

% git show --oneline -s
91d76b28 (HEAD -> master, origin/master, origin/HEAD) Alire.Manifest: Remove "Added by alr" comments (#977)

[mosteo]

Looks good, thanks @wiremoons