Pass default flags before custom flags to allow overriding

Target-specific copts should override "default" ones coming from the objc fragment.

Closes #10894.

PiperOrigin-RevId: 299062881
diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java b/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
index a81f873..2999edf 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/CompilationSupport.java
@@ -305,11 +305,11 @@
             .addCcCompilationContexts(objcCompilationContext.getDepCcCompilationContexts())
             .setCopts(
                 ImmutableList.<String>builder()
-                    .addAll(getCompileRuleCopts())
                     .addAll(
                         ruleContext
                             .getFragment(ObjcConfiguration.class)
                             .getCoptsForCompilationMode())
+                    .addAll(getCompileRuleCopts())
                     .addAll(extraCompileArgs)
                     .addAll(
                         pathsToIncludeArgs(objcCompilationContext.getStrictDependencyIncludes()))