build: Remove the obsolete makefiles

Remove all makefiles that used to serve specific Unix and Unix-ish
operating systems. We still retain the generic Unix makefile.std,
as well as the compiler-specific (Unix and non-Unix) makefiles and
scripts.

Update scripts/README.md and manuals/libpng-install.txt accordingly.

manuals/libpng-install.txt

@@ -303,8 +303,6 @@ or more of
    CPPFLAGS += "-DPNG_INTEL_SSE"
    CPPFLAGS += "-DPNG_POWERPC_VSX"
 
-See for example scripts/makefile.linux-opt
-
 If you wish to avoid using them,
 you can disable them via the configure option
 

scripts/README.md

@@ -1,73 +1,43 @@
-Scripts and makefiles for libpng
---------------------------------
+Makefiles for libpng
+--------------------
 
-    pnglibconf.h.prebuilt  =>  Configuration settings
+    makefile.amiga     =>  Amiga makefile
+    makefile.atari     =>  Atari makefile
+    makefile.clang     =>  Generic clang makefile
+    makefile.emcc      =>  Emscripten makefile
+    makefile.gcc       =>  Generic gcc makefile
+    makefile.ibmc      =>  IBM C/C++ version 3.x for Win32 and OS/2
+    makefile.intel     =>  Intel C/C++ version 4.0 and later
+    makefile.riscos    =>  Acorn RISCOS makefile
+    makefile.std       =>  Generic UNIX makefile
+    makefile.vcwin32       =>  Microsoft Visual C++ for Windows/x86
+    makefile.vcwin-arm64   =>  Microsoft Visual C++ for Windows/ARM64
+    makevms.com        =>  VMS build script
+    descrip.mms        =>  VMS makefile for MMS or MMK
+    smakefile.ppc      =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
+                           (Requires SCOPTIONS, copied from SCOPTIONS.ppc)
+    SCOPTIONS.ppc      =>  Used with smakefile.ppc
 
-    makefile.aix      =>  AIX/gcc makefile
-    makefile.amiga    =>  Amiga makefile
-    makefile.atari    =>  Atari makefile
-    makefile.bc32     =>  Borland C makefile, for Win32
-    makefile.beos     =>  BeOS makefile
-    makefile.clang    =>  Generic clang makefile
-    makefile.darwin   =>  Darwin makefile, for macOS (formerly Mac OS X)
-    makefile.dec      =>  DEC Alpha UNIX makefile
-    makefile.dj2      =>  DJGPP 2 makefile
-    makefile.emcc     =>  Emscripten makefile
-    makefile.freebsd  =>  FreeBSD makefile
-    makefile.gcc      =>  Generic gcc makefile
-    makefile.hpgcc    =>  HPUX makefile using gcc
-    makefile.hpux     =>  HPUX (10.20 and 11.00) makefile
-    makefile.hp64     =>  HPUX (10.20 and 11.00) makefile, 64-bit
-    makefile.ibmc     =>  IBM C/C++ version 3.x for Win32 and OS/2 (static lib)
-    makefile.intel    =>  Intel C/C++ version 4.0 and later
-    makefile.linux    =>  Linux/ELF makefile
-                          (gcc, creates shared libpng18.so.18.1.8.*)
-    makefile.mips     =>  MIPS makefile
-    makefile.msys     =>  MSYS (MinGW) makefile
-    makefile.netbsd   =>  NetBSD/cc makefile, makes shared libpng.so
-    makefile.openbsd  =>  OpenBSD makefile
-    makefile.riscos   =>  Acorn RISCOS makefile
-    makefile.sco      =>  SCO OSr5 ELF and Unixware 7 with Native cc
-    makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, static lib)
-    makefile.sggcc    =>  Silicon Graphics makefile
-                          (gcc, creates shared libpng18.so.18.1.8.*)
-    makefile.solaris  =>  Solaris 2.X makefile
-                          (gcc, creates shared libpng18.so.18.1.8.*)
-    makefile.so9      =>  Solaris 9 makefile
-                          (gcc, creates shared libpng18.so.18.1.8.*)
-    makefile.std      =>  Generic UNIX makefile (cc, static lib)
-    makefile.sunos    =>  Sun makefile
-    makefile.32sunu   =>  Sun Ultra 32-bit makefile
-    makefile.64sunu   =>  Sun Ultra 64-bit makefile
-    makefile.vcwin32  =>  makefile for Microsoft Visual C++ 4.0 and later
-    makevms.com       =>  VMS build script
-    smakefile.ppc     =>  AMIGA smakefile for SAS C V6.58/7.00 PPC compiler
-                          (Requires SCOPTIONS, copied from SCOPTIONS.ppc)
+Other supporting files and scripts
+----------------------------------
 
-Other supporting scripts
-------------------------
-
-    README.txt        =>  This file
-    descrip.mms       =>  VMS makefile for MMS or MMK
-    libpng-config-body.in  =>  used by several makefiles to create libpng-config
-    libpng-config-head.in  =>  used by several makefiles to create libpng-config
-    libpng.pc.in      =>  Used by several makefiles to create libpng.pc
-    macro.lst         =>  Used by GNU Autotools
-    pngwin.rc         =>  Used by the visualc71 project
-    pngwin.def        =>  Used by makefile.os2
-    pngwin.dfn        =>  Used to maintain pngwin.def
-    SCOPTIONS.ppc     =>  Used with smakefile.ppc
-
-    checksym.awk      =>  Used for maintaining pnglibconf.h
-    dfn.awk           =>  Used for maintaining pnglibconf.h
-    options.awk       =>  Used for maintaining pnglibconf.h
-    pnglibconf.dfa    =>  Used for maintaining pnglibconf.h
-    pnglibconf.mak    =>  Used for maintaining pnglibconf.h
-    intprefix.c       =>  Used for symbol versioning
-    prefix.c          =>  Used for symbol versioning
-    sym.c             =>  Used for symbol versioning
-    symbols.c         =>  Used for symbol versioning
-    vers.c            =>  Used for symbol versioning
+    pnglibconf.h.prebuilt  =>  Pre-built configuration settings
+    libpng-config-body.in  =>  Used by several makefiles to create libpng-config
+    libpng-config-head.in  =>  Used by several makefiles to create libpng-config
+    libpng.pc.in       =>  Used by several makefiles to create libpng.pc
+    macro.lst          =>  Used by GNU Autotools
+    pngwin.rc          =>  Used by the Visual Studio project
+    checksym.awk       =>  Used for maintaining pnglibconf.h
+    dfn.awk            =>  Used for maintaining pnglibconf.h
+    options.awk        =>  Used for maintaining pnglibconf.h
+    pnglibconf.dfa     =>  Used for maintaining pnglibconf.h
+    pnglibconf.mak     =>  Used for maintaining pnglibconf.h
+    intprefix.c        =>  Used for symbol versioning
+    prefix.c           =>  Used for symbol versioning
+    sym.c              =>  Used for symbol versioning
+    symbols.c          =>  Used for symbol versioning
+    vers.c             =>  Used for symbol versioning
+    README.txt         =>  This file
 
 Further information can be found in comments in the individual scripts and
 makefiles.