Revert "Set a lower limit for max variables"

This reverts commit 377cbe5.

Reason for revert: Experiment concluded, knowledge gained, further
actions will be taken in follow-ups.

The high number of variables appear when importing some test case(s)
defining array literals with thousands of entries.
Those imported test cases originate as far as we can tell from JS test
cases, not from Fuzzilli itself generating such huge cases.

Bug: 433646300
Original change's description:
> Set a lower limit for max variables
>
> Bug: 433646300
> Change-Id: Icbcf88d431a255a3f6df6ca113e6c784e5b96e2c
> Reviewed-on: https://chrome-internal-review.googlesource.com/c/v8/fuzzilli/+/8446876
> Reviewed-by: Carl Smith <[email protected]>
> Reviewed-by: Michael Achenbach <[email protected]>
> Commit-Queue: Matthias Liedtke <[email protected]>

Bug: 433646300
Change-Id: Ibec37070a30fd3f70a588028a4c96a507475fe97
Reviewed-on: https://chrome-internal-review.googlesource.com/c/v8/fuzzilli/+/8451656
Commit-Queue: Matthias Liedtke <[email protected]>
Bot-Commit: Rubber Stamper <[email protected]>

Author: Liedtke

Sources/Fuzzilli/Base/ProgramBuilder.swift

@@ -3997,13 +3997,7 @@ public class ProgramBuilder {
 
     /// Returns the next free variable.
     func nextVariable() -> Variable {
-        // Temporarily introduce a lower limit: Programs shouldn't get exceedingly large.
-        // TODO(mliedtke): Undo this once the issues are fixed.
-        let maxNumberOfVariables = 10_000
-        assert(maxNumberOfVariables <= Code.maxNumberOfVariables)
-        if numVariables >= maxNumberOfVariables {
-            fatalError("Too many variables \(numVariables). Contributors: \(contributors.map {$0.name})")
-        }
+        assert(numVariables < Code.maxNumberOfVariables, "Too many variables")
         numVariables += 1
         return Variable(number: numVariables - 1)
     }