Revert "Remove warnings of flip-flop deprecation from tests and specs"

This reverts commit bf7a32d220.

flip-flop is no longer deprecated.

[Feature #5400]

spec/ruby/command_line/dash_e_spec.rb

@@ -25,7 +25,7 @@ describe "The -e command line option" do
 
   describe "with -n and a Fixnum range" do
     before :each do
-      @script = "-W0 -ne 'print if %s' #{fixture(__FILE__, "conditional_range.txt")}"
+      @script = "-ne 'print if %s' #{fixture(__FILE__, "conditional_range.txt")}"
     end
 
     it "mimics an awk conditional by comparing an inclusive-end range with $." do

spec/ruby/language/if_spec.rb

@@ -233,22 +233,19 @@ describe "The if expression" do
   describe "with a boolean range ('flip-flop' operator)" do
     before :each do
       ScratchPad.record []
-      @verbose = $VERBOSE
-      $VERBOSE = nil
     end
 
     after :each do
       ScratchPad.clear
-      $VERBOSE = @verbose
     end
 
     it "mimics an awk conditional with a single-element inclusive-end range" do
-      eval "10.times { |i| ScratchPad << i if (i == 4)..(i == 4) }"
+      10.times { |i| ScratchPad << i if (i == 4)..(i == 4) }
       ScratchPad.recorded.should == [4]
     end
 
     it "mimics an awk conditional with a many-element inclusive-end range" do
-      eval "10.times { |i| ScratchPad << i if (i == 4)..(i == 7) }"
+      10.times { |i| ScratchPad << i if (i == 4)..(i == 7) }
       ScratchPad.recorded.should == [4, 5, 6, 7]
     end
 
@@ -258,12 +255,12 @@ describe "The if expression" do
     end
 
     it "mimics a sed conditional with a many-element exclusive-end range" do
-      eval "10.times { |i| ScratchPad << i if (i == 4)...(i == 5) }"
+      10.times { |i| ScratchPad << i if (i == 4)...(i == 5) }
       ScratchPad.recorded.should == [4, 5]
     end
 
     it "allows combining two flip-flops" do
-      eval "10.times { |i| ScratchPad << i if (i == 4)...(i == 5) or (i == 7)...(i == 8) }"
+      10.times { |i| ScratchPad << i if (i == 4)...(i == 5) or (i == 7)...(i == 8) }
       ScratchPad.recorded.should == [4, 5, 7, 8]
     end
 
@@ -281,18 +278,18 @@ describe "The if expression" do
 
     it "evaluates the second conditions lazily with inclusive-end range" do
       collector = proc { |i| ScratchPad << i }
-      eval "10.times { |i| i if (i == 4)...collector[i] }"
+      10.times { |i| i if (i == 4)...collector[i] }
       ScratchPad.recorded.should == [5]
     end
 
     it "evaluates the second conditions lazily with exclusive-end range" do
       collector = proc { |i| ScratchPad << i }
-      eval "10.times { |i| i if (i == 4)..collector[i] }"
+      10.times { |i| i if (i == 4)..collector[i] }
       ScratchPad.recorded.should == [4]
     end
 
     it "scopes state by flip-flop" do
-      store_me = eval("proc { |i| ScratchPad << i if (i == 4)..(i == 7) }")
+      store_me = proc { |i| ScratchPad << i if (i == 4)..(i == 7) }
       store_me[1]
       store_me[4]
       proc { store_me[1] }.call

spec/ruby/language/precedence_spec.rb

@@ -301,10 +301,8 @@ describe "Operators" do
    from = 1
    to = 2
    # These are Range instances, not flip-flop
-   suppress_warning do
-     (eval("from..to") ? 3 : 4).should == 3
-     (eval("from...to") ? 3 : 4).should == 3
-   end
+   (from..to ? 3 : 4).should == 3
+   (from...to ? 3 : 4).should == 3
  end
 
   it "? : is right-associative" do

test/ruby/test_flip.rb

@@ -2,16 +2,7 @@
 require 'test/unit'
 
 class TestFlip < Test::Unit::TestCase
-  def setup
-    @verbose_bak, $VERBOSE = $VERBOSE, nil
-  end
-
-  def teardown
-    $VERBOSE = @verbose_bak
-  end
-
   def test_flip_flop
-    eval <<-END
     assert_equal [4,5], (1..9).select {|n| true if (n==4)..(n==5)}
     assert_equal [4,5], (1..9).select {|n| true if (n==4)...(n==5)}
     assert_equal [2], (1..9).select {|n| true if (n==2)..(n%2).zero?}
@@ -19,7 +10,6 @@ class TestFlip < Test::Unit::TestCase
     assert_equal [4,5,7,8], (1..9).select {|n| true if (n==4)...(n==5) or (n==7)...(n==8)}
     assert_equal [nil, 2, 3, 4, nil], (1..5).map {|x| x if (x==2..x==4)}
     assert_equal [1, nil, nil, nil, 5], (1..5).map {|x| x if !(x==2..x==4)}
-    END
   end
 
   def test_hidden_key
@@ -35,14 +25,14 @@ class TestFlip < Test::Unit::TestCase
   def test_shared_eval
     bug7671 = '[ruby-core:51296]'
     vs = (1..9).to_a
-    eval("vs.select {|n| if n==2..n==16 then 1 end}")
+    vs.select {|n| if n==2..n==16 then 1 end}
     v = eval("vs.select {|n| if n==3..n==6 then 1 end}")
     assert_equal([*3..6], v, bug7671)
     vs
   end
 
   def test_shared_thread
-    ff = eval("proc {|n| true if n==3..n==5}")
+    ff = proc {|n| true if n==3..n==5}
     v = 1..9
     a = true
     th = Thread.new {

test/ruby/test_jit.rb

@@ -112,13 +112,10 @@ class TestJIT < Test::Unit::TestCase
   end
 
   def test_compile_insn_setspecial
-    verbose_bak, $VERBOSE = $VERBOSE, nil
     assert_compile_once("#{<<~"begin;"}\n#{<<~"end;"}", result_inspect: 'true', insns: %i[setspecial])
     begin;
       true if nil.nil?..nil.nil?
     end;
-  ensure
-    $VERBOSE = verbose_bak
   end
 
   def test_compile_insn_instancevariable