main: accept and ignore auto-image-base linker options

Closes #19613.

Author: alexrp

src/main.zig

@@ -2516,6 +2516,20 @@ fn buildOutputType(
                     stack_size = parseStackSize(linker_args_it.nextOrFatal());
                 } else if (mem.eql(u8, arg, "--image-base")) {
                     image_base = parseImageBase(linker_args_it.nextOrFatal());
+                } else if (mem.eql(u8, arg, "--enable-auto-image-base") or
+                    mem.eql(u8, arg, "--disable-auto-image-base"))
+                {
+                    // `--enable-auto-image-base` is a flag that binutils added in ~2000 for MinGW.
+                    // It does a hash of the file and uses that as part of the image base value.
+                    // Presumably the idea was to avoid DLLs needing to be relocated when loaded.
+                    // This is practically irrelevant today as all PEs produced since Windows Vista
+                    // have ASLR enabled by default anyway, and Windows 10+ has Mandatory ASLR which
+                    // doesn't even care what the PE file wants and relocates it anyway.
+                    //
+                    // Unfortunately, Libtool hardcodes usage of this archaic flag when targeting
+                    // MinGW, so to make `zig cc` for that use case work, accept and ignore the
+                    // flag, and warn the user that it has no effect.
+                    warn("auto-image-base options are unimplemented and ignored", .{});
                 } else if (mem.eql(u8, arg, "-T") or mem.eql(u8, arg, "--script")) {
                     linker_script = linker_args_it.nextOrFatal();
                 } else if (mem.eql(u8, arg, "--eh-frame-hdr")) {