Add HPPA and sparc64 architectures (#20934)

* Add comments on CPU arch detection

* Support HPPA/hppa/parisc64 CPU architecture

* Support sparc64 CPU architecture

* Update tools/niminst/makefile.nimf

Co-authored-by: Andreas Rumpf <rumpf_a@web.de>

lib/system/platforms.nim

@@ -10,6 +10,8 @@
 ## Platform detection for NimScript. This module is included by the system module!
 ## Do not import it directly!
 
+# CPU architectures have alias names mapped in tools/niminst/makefile.nimf
+
 type
   CpuPlatform* {.pure.} = enum ## the CPU this program will run on.
     none,                      ## unknown CPU

tools/niminst/makefile.nimf

@@ -16,6 +16,7 @@ endif
 
 target := ?{"$(binDir)/" & toLowerAscii(c.name)}
 
+
 ucpu := $(shell sh -c 'uname -m | tr "[:upper:]" "[:lower:]"')
 ifeq ($(OS),Windows_NT)
   uos := windows
@@ -103,12 +104,18 @@ endif
 ifeq ($(ucpu),x86_64)
   mycpu = amd64
 endif
+ifeq ($(ucpu),parisc64)
+  mycpu = hppa
+endif
 ifeq ($(ucpu),s390x)
   mycpu = s390x
 endif
 ifeq ($(ucpu),sparc)
   mycpu = sparc
 endif
+ifeq ($(ucpu),sparc64)
+  mycpu = sparc64
+endif
 ifeq ($(ucpu),sun)
   mycpu = sparc
 endif