Enable ANGLE_ASSERT_ALWAYS_ON when building with libFuzzer

https://bugs.webkit.org/show_bug.cgi?id=269206
<rdar://122811102>

Reviewed by Kimmo Kinnunen.

* Source/ThirdParty/ANGLE/Configurations/BaseTarget.xcconfig:
(GCC_PREPROCESSOR_DEFINITIONS):
(GCC_PREPROCESSOR_DEFINITIONS_LIBFUZZER_YES): Add.
- Define ANGLE_ASSERT_ALWAYS_ON macro when ENABLE_LIBFUZZER is YES.

Canonical link: https://commits.webkit.org/274485@main

Source/ThirdParty/ANGLE/Configurations/BaseTarget.xcconfig

@@ -29,7 +29,8 @@ HEADER_SEARCH_PATHS = ${DERIVED_FILES_DIR} $(ANGLE_HEADER_PATH_PREFIX)/WebKit $(
 
 USE_HEADERMAP = NO;
 
-GCC_PREPROCESSOR_DEFINITIONS = $(DEBUG_DEFINES) LIBGLESV2_IMPLEMENTATION LIBANGLE_IMPLEMENTATION ANGLE_CAPTURE_ENABLED=0 ANGLE_ENABLE_METAL ANGLE_METAL_XCODE_BUILDS_SHADERS ANGLE_ENABLE_METAL_OWNERSHIP_IDENTITY $(GCC_PREPROCESSOR_DEFINITIONS_$(WK_PLATFORM_NAME));
+GCC_PREPROCESSOR_DEFINITIONS = $(DEBUG_DEFINES) LIBGLESV2_IMPLEMENTATION LIBANGLE_IMPLEMENTATION ANGLE_CAPTURE_ENABLED=0 ANGLE_ENABLE_METAL ANGLE_METAL_XCODE_BUILDS_SHADERS ANGLE_ENABLE_METAL_OWNERSHIP_IDENTITY $(GCC_PREPROCESSOR_DEFINITIONS_$(WK_PLATFORM_NAME)) $(GCC_PREPROCESSOR_DEFINITIONS_LIBFUZZER_$(ENABLE_LIBFUZZER));
 GCC_PREPROCESSOR_DEFINITIONS_macosx = ANGLE_ENABLE_GLSL ANGLE_ENABLE_ESSL ANGLE_ENABLE_OPENGL ANGLE_ENABLE_GL_DESKTOP_BACKEND ANGLE_ENABLE_APPLE_WORKAROUNDS ANGLE_ENABLE_CGL GL_SILENCE_DEPRECATION;
 GCC_PREPROCESSOR_DEFINITIONS_maccatalyst = $(GCC_PREPROCESSOR_DEFINITIONS_macosx);
 GCC_PREPROCESSOR_DEFINITIONS_maccatalyst[arch=arm*] = $(GCC_PREPROCESSOR_DEFINITIONS_macosx) ANGLE_ENABLE_EAGL GLES_SILENCE_DEPRECATION ANGLE_CPU_ARM64;
+GCC_PREPROCESSOR_DEFINITIONS_LIBFUZZER_YES = ANGLE_ASSERT_ALWAYS_ON;