[llvm-objcopy][COFF] Add aliases for some --subsystem options (llvm#98036)

GNU objcopy has some --subsystem options that aren't present in LLVM's.
They are in fact just aliases to some of the existing options.

For the sake of compatibility with the GNU toolchain, this patch adds
these aliases to LLVM objcopy.

The alias list is not exhaustive as this is an incremental change.

Author: vhscampos

llvm/test/tools/llvm-objcopy/COFF/subsystem.test

@@ -30,6 +30,27 @@
 # INVALID-MAJOR-NUMBER: 'foo' is not a valid subsystem major version
 # INVALID-MINOR-NUMBER: 'bar' is not a valid subsystem minor version
 
+# RUN: llvm-objcopy --subsystem=efi_application %t.in.exe %t.out.exe
+# RUN: llvm-readobj --file-headers %t.out.exe | FileCheck %s --check-prefix=EFI-APPLICATION
+# RUN: llvm-objcopy --subsystem=efi-app %t.in.exe %t.out.exe
+# RUN: llvm-readobj --file-headers %t.out.exe | FileCheck %s --check-prefix=EFI-APPLICATION
+
+# EFI-APPLICATION: Subsystem: IMAGE_SUBSYSTEM_EFI_APPLICATION
+
+# RUN: llvm-objcopy --subsystem=efi_boot_service_driver %t.in.exe %t.out.exe
+# RUN: llvm-readobj --file-headers %t.out.exe | FileCheck %s --check-prefix=EFI-BOOT-SERVICE-DRIVER
+# RUN: llvm-objcopy --subsystem=efi-bsd %t.in.exe %t.out.exe
+# RUN: llvm-readobj --file-headers %t.out.exe | FileCheck %s --check-prefix=EFI-BOOT-SERVICE-DRIVER
+
+# EFI-BOOT-SERVICE-DRIVER: Subsystem: IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER
+
+# RUN: llvm-objcopy --subsystem=efi_runtime_driver %t.in.exe %t.out.exe
+# RUN: llvm-readobj --file-headers %t.out.exe | FileCheck %s --check-prefix=EFI-RUNTIME-DRIVER
+# RUN: llvm-objcopy --subsystem=efi-rtd %t.in.exe %t.out.exe
+# RUN: llvm-readobj --file-headers %t.out.exe | FileCheck %s --check-prefix=EFI-RUNTIME-DRIVER
+
+# EFI-RUNTIME-DRIVER: Subsystem: IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER
+
 --- !COFF
 OptionalHeader:
   AddressOfEntryPoint: 4096

llvm/tools/llvm-objcopy/ObjcopyOptions.cpp

@@ -710,12 +710,13 @@ objcopy::parseObjcopyOptions(ArrayRef<const char *> RawArgsArr,
             .Case("boot_application",
                   COFF::IMAGE_SUBSYSTEM_WINDOWS_BOOT_APPLICATION)
             .Case("console", COFF::IMAGE_SUBSYSTEM_WINDOWS_CUI)
-            .Case("efi_application", COFF::IMAGE_SUBSYSTEM_EFI_APPLICATION)
-            .Case("efi_boot_service_driver",
-                  COFF::IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER)
+            .Cases("efi_application", "efi-app",
+                   COFF::IMAGE_SUBSYSTEM_EFI_APPLICATION)
+            .Cases("efi_boot_service_driver", "efi-bsd",
+                   COFF::IMAGE_SUBSYSTEM_EFI_BOOT_SERVICE_DRIVER)
             .Case("efi_rom", COFF::IMAGE_SUBSYSTEM_EFI_ROM)
-            .Case("efi_runtime_driver",
-                  COFF::IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER)
+            .Cases("efi_runtime_driver", "efi-rtd",
+                   COFF::IMAGE_SUBSYSTEM_EFI_RUNTIME_DRIVER)
             .Case("native", COFF::IMAGE_SUBSYSTEM_NATIVE)
             .Case("posix", COFF::IMAGE_SUBSYSTEM_POSIX_CUI)
             .Case("windows", COFF::IMAGE_SUBSYSTEM_WINDOWS_GUI)