$_ = join'',<DATA>;
(my $re=$_) =~ s/(({)|(})|.)/${['(','']}[!$2]\Q$1\E${[')','']}[!$3]/gs
+;
$re = join'|',map quotemeta,eval{/$re/};
warn $@ if $@ =~ /unmatched/;
print join "\n",/(\bfunction\b[^()]*\([^()]*\)\s*(?:$re))/g,'';


__DATA__

 function functStart () {};
 var g1, g2 = __QUOTE__; var g3 = 10000000;
 if (g1) { var XXXXXXX = __QUOTE__; }
 if ( ! defaultCookieCrumbNav ) { cookieCrumbNavBarHTML = __QUOTE__ ; 
+} 
 else { function funct1 () { }; var xxx = __QUOTE__ ; }
 if (true == false) { alert(var1); }
 if (1) { if (1) { function funct2 (X) { x = funct3 (1,2); }; function
+ funct3 () { alert(1); } } }

 function funct4 (a,b) { alert (1,2,3,4); return (a + b); }
 function funct5 () { var aaa = 1; }

 var g4; var g7 = __QUOTE__;

 function funct6 () { var b = __REGEX__; c = __REGEX__; if (test333())
+ { return true; } }
 function funct7 () { var a = 111; }
 alert ( 3 );
 funct5 ( funct6 ( funct2 () ) );
 function functEnd () {}
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