[JavaScriptCore] strstr->strchr when string is only one letter long

https://bugs.webkit.org/show_bug.cgi?id=267351

Reviewed by Michael Catanzaro.

Instead of having to find a whole string, we can just find the char we
need.

* Source/JavaScriptCore/runtime/Options.cpp: strstr->strchr
(JSC::Options::setOptions): Ditto.
* Source/JavaScriptCore/tools/FunctionOverrides.cpp: Ditto.
(JSC::parseClause): Ditto.

Canonical link: https://commits.webkit.org/272859@main

Source/JavaScriptCore/runtime/Options.cpp

@@ -1025,7 +1025,7 @@ bool Options::setOptions(const char* optionsStr)
             break;
 
         char* optionStart = p;
-        p = strstr(p, "=");
+        p = strchr(p, '=');
         if (!p) {
             dataLogF("'=' not found in option string: %p\n", optionStart);
             WTF::fastFree(optionsStrCopy);

Source/JavaScriptCore/tools/FunctionOverrides.cpp

@@ -214,7 +214,7 @@ static String parseClause(const char* keyword, size_t keywordLength, FILE* file,
         FAIL_WITH_ERROR(SYNTAX_ERROR, ("'", keyword, "' must be followed by a ' ':\n", line, "\n"));
 
     const char* delimiterStart = &line[keywordLength + 1];
-    const char* delimiterEnd = strstr(delimiterStart, "{");
+    const char* delimiterEnd = strchr(delimiterStart, '{');
     if (!delimiterEnd)
         FAIL_WITH_ERROR(SYNTAX_ERROR, ("Missing { after '", keyword, "' clause start delimiter:\n", line, "\n"));