Swift: Use regexp for function name.

swift/ql/lib/codeql/swift/elements/decl/Function.qll

@@ -6,6 +6,16 @@ private import codeql.swift.elements.decl.Method
  */
 class Function extends Generated::Function, Callable {
   override string toString() { result = this.getName() }
+
+  /**
+   * Gets the name of this function, without the argument list. For example
+   * a function with name `myFunction(arg:)` has short name `myFunction`.
+   */
+  string getShortName() {
+    // match as many characters as possible that are not `(`.
+    // (`*+` is possessive matching)
+    result = this.getName().regexpCapture("([^(]*+).*", 1)
+  }
 }
 
 /**

swift/ql/lib/codeql/swift/security/SensitiveExprs.qll

@@ -102,7 +102,7 @@ private class SensitiveFunction extends Function {
   string name; // name of the function, not including the argument list.
 
   SensitiveFunction() {
-    name = this.getName().splitAt("(", 0) and
+    name = this.getShortName() and
     name.regexpMatch(sensitiveType.getRegexp())
   }