Do not pass -Wl,-headerpad_max_install_names to b-linux-path

One of the more curious bugs, if you use
-Wl,-headerpad_max_install_names on linux, it tries to link a library
named "eaderpath_max_install_names" in, which causes all kinds of weird
havoc.

Most notably, gtester inside glib fails to run for bizarre reasons.
-Wl,-headerpad_max_install_names is not an option anywhere outside macos
anyway, so move it to macos only and avoid the heartache of extremely
weild bugs.

Library/Homebrew/extend/ENV/std.rb

@@ -55,8 +55,6 @@ module Stdenv
     # Os is the default Apple uses for all its stuff so let's trust them
     define_cflags "-Os #{SAFE_CFLAGS_FLAGS}"
 
-    append "LDFLAGS", "-Wl,-headerpad_max_install_names"
-
     send(compiler)
 
     return unless cc&.match?(GNU_GCC_REGEXP)

Library/Homebrew/extend/os/mac/extend/ENV/std.rb

@@ -16,6 +16,8 @@ module Stdenv
       bottle_arch: bottle_arch, testing_formula: testing_formula
     )
 
+    append "LDFLAGS", "-Wl,-headerpad_max_install_names"
+
     # sed is strict, and errors out when it encounters files with
     # mixed character sets
     delete("LC_ALL")