Cherry-pick 80eedd6. rdar://114455833

    Add support for `make LIBFUZZER=YES`
    https://bugs.webkit.org/show_bug.cgi?id=259369
    rdar://112621746

    Reviewed by Alex Christensen.

    * Makefile.shared:
    - Add support for `make LIBFUZZER=YES` and
      `make LIBFUZZER=NO`.

    Canonical link: https://commits.webkit.org/266593@main

Identifier: 265870.443@safari-7616-branch

Makefile.shared

@@ -93,6 +93,14 @@ CONFIG_OPTIONS += --no-asan
 endif
 endif
 
+ifeq ($(LIBFUZZER),YES)
+CONFIG_OPTIONS += --libfuzzer
+else
+ifeq ($(LIBFUZZER),NO)
+CONFIG_OPTIONS += --no-libfuzzer
+endif
+endif
+
 ifeq ($(TSAN),YES)
 CONFIG_OPTIONS += --tsan
 else