Add support for 64-bit SPARC as a separate architecture

Previously, sparc64 was defined as an alias for the 32-bit SPARC
architecture which was true while SPARC mainland was mostly 32
bits. More recently, 64-bit SPARC has become a port of its own,
so it needs to be treated as a separate architecture.

Cabal-syntax/src/Distribution/System.hs

@@ -182,13 +182,12 @@ buildOS = classifyOS Permissive System.Info.os
 -- ------------------------------------------------------------
 
 -- | These are the known Arches: I386, X86_64, PPC, PPC64, Sparc,
--- Arm, AArch64, Mips, SH, IA64, S390, S390X, Alpha, Hppa, Rs6000,
--- M68k, Vax, RISCV64, LoongArch64, JavaScript and Wasm32.
+-- Sparc64, Arm, AArch64, Mips, SH, IA64, S390, S390X, Alpha, Hppa,
+-- Rs6000, M68k, Vax, RISCV64, LoongArch64, JavaScript and Wasm32.
 --
 -- The following aliases can also be used:
 --    * PPC alias: powerpc
 --    * PPC64 alias : powerpc64, powerpc64le
---    * Sparc aliases: sparc64, sun4
 --    * Mips aliases: mipsel, mipseb
 --    * Arm aliases: armeb, armel
 --    * AArch64 aliases: arm64
@@ -198,6 +197,7 @@ data Arch
   | PPC
   | PPC64
   | Sparc
+  | Sparc64
   | Arm
   | AArch64
   | Mips
@@ -228,6 +228,7 @@ knownArches =
   , PPC
   , PPC64
   , Sparc
+  , Sparc64
   , Arm
   , AArch64
   , Mips
@@ -251,7 +252,6 @@ archAliases Strict _ = []
 archAliases Compat _ = []
 archAliases _ PPC = ["powerpc"]
 archAliases _ PPC64 = ["powerpc64", "powerpc64le"]
-archAliases _ Sparc = ["sparc64", "sun4"]
 archAliases _ Mips = ["mipsel", "mipseb"]
 archAliases _ Arm = ["armeb", "armel"]
 archAliases _ AArch64 = ["arm64"]

Cabal/src/Distribution/Simple/PreProcess.hs

@@ -850,6 +850,7 @@ platformDefines lbi =
       PPC -> ["powerpc"]
       PPC64 -> ["powerpc64"]
       Sparc -> ["sparc"]
+      Sparc64 -> ["sparc64"]
       Arm -> ["arm"]
       AArch64 -> ["aarch64"]
       Mips -> ["mips"]