feat(native-comp): no longer require gcc homebrew formula

This finally makes Emacs.app with native-comp fully self-contained, no
longer requiring the GCC Homebrew formula to be installed when
loading *.eln files that link against
/usr/local/lib/gcc/11/libgcc_s.1.dylib.

By adding the signing entitlement
com.apple.security.cs.allow-dyld-environment-variables, which allows
dynamic library loading to be controlled via DYLD_* environment
variables. It seems the lack of this was preventing Emacs from loading
the bundled libgcc_s.1.dylib file from Contents/Frameworks.

Fixes jimeh#53

Author: jimeh

pkg/sign/entitlements.go

@@ -14,6 +14,7 @@ var DefaultEmacsEntitlements = []string{
 	"com.apple.security.cs.allow-jit",
 	"com.apple.security.network.client",
 	"com.apple.security.cs.disable-library-validation",
+	"com.apple.security.cs.allow-dyld-environment-variables",
 	"com.apple.security.automation.apple-events",
 }
 

pkg/sign/entitlements_test.go

@@ -50,6 +50,7 @@ var entitlementsTestCases = []struct {
 			"com.apple.security.cs.allow-jit",
 			"com.apple.security.network.client",
 			"com.apple.security.cs.disable-library-validation",
+			"com.apple.security.cs.allow-dyld-environment-variables",
 			"com.apple.security.automation.apple-events",
 		},
 		//nolint:lll
@@ -64,6 +65,8 @@ var entitlementsTestCases = []struct {
                 <true/>
                 <key>com.apple.security.cs.disable-library-validation</key>
                 <true/>
+                <key>com.apple.security.cs.allow-dyld-environment-variables</key>
+                <true/>
                 <key>com.apple.security.automation.apple-events</key>
                 <true/>
               </dict>
@@ -78,6 +81,7 @@ func TestDefaultEmacsEntitlements(t *testing.T) {
 			"com.apple.security.cs.allow-jit",
 			"com.apple.security.network.client",
 			"com.apple.security.cs.disable-library-validation",
+			"com.apple.security.cs.allow-dyld-environment-variables",
 			"com.apple.security.automation.apple-events",
 		},
 		DefaultEmacsEntitlements,