[JSC] Suppress coverage_sanitizer on Fuzzilli::initializeCoverage()

https://bugs.webkit.org/show_bug.cgi?id=265507
<rdar://118908398>

Reviewed by Yusuke Suzuki.

* Source/JavaScriptCore/fuzzilli/Fuzzilli.cpp:
(Fuzzilli::initializeCoverage):
- Suppress coverage sanitizer when initializing coverage.

* Source/WTF/wtf/Compiler.h:
(COVERAGE_ENABLED): Add.
(SUPPRESS_COVERAGE): Add.
- Add macros used with -fsanitize-coverage.

Canonical link: https://commits.webkit.org/271277@main

Source/JavaScriptCore/fuzzilli/Fuzzilli.cpp

@@ -23,6 +23,7 @@
 
 #include <mutex>
 #include <wtf/Assertions.h>
+#include <wtf/Compiler.h>
 #include <wtf/DataLog.h>
 #include <wtf/NeverDestroyed.h>
 
@@ -77,6 +78,7 @@ void Fuzzilli::waitForCommand()
     RELEASE_ASSERT_WITH_MESSAGE(action == 'cexe', "[REPRL] Unknown action: %u", action);
 }
 
+SUPPRESS_COVERAGE
 void Fuzzilli::initializeCoverage(uint32_t* start, uint32_t* stop)
 {
     RELEASE_ASSERT_WITH_MESSAGE(!edgesStart && !edgesStop, "Coverage instrumentation is only supported for a single module");

Source/WTF/wtf/Compiler.h

@@ -170,6 +170,16 @@
 #define SUPPRESS_TSAN
 #endif
 
+/* COVERAGE_ENABLED and SUPPRESS_COVERAGE */
+
+#define COVERAGE_ENABLED COMPILER_HAS_CLANG_FEATURE(coverage_sanitizer)
+
+#if COVERAGE_ENABLED
+#define SUPPRESS_COVERAGE __attribute__((no_sanitize("coverage")))
+#else
+#define SUPPRESS_COVERAGE
+#endif
+
 /* ==== Compiler-independent macros for various compiler features, in alphabetical order ==== */
 
 /* ALWAYS_INLINE */