Fix exception message to match CRuby when Integer#chr is called with incorrect codepoint value

* close oracle/truffleruby#2795

Author: andrykonchin

core/integer/chr_spec.rb

@@ -10,12 +10,12 @@
   end
 
   it "raises a RangeError is self is less than 0" do
-    -> { -1.chr }.should raise_error(RangeError)
-    -> { (-bignum_value).chr }.should raise_error(RangeError)
+    -> { -1.chr }.should raise_error(RangeError, /-1 out of char range/)
+    -> { (-bignum_value).chr }.should raise_error(RangeError, /bignum out of char range/)
   end
 
   it "raises a RangeError if self is too large" do
-    -> { 2206368128.chr(Encoding::UTF_8) }.should raise_error(RangeError)
+    -> { 2206368128.chr(Encoding::UTF_8) }.should raise_error(RangeError, /2206368128 out of char range/)
   end
 
   describe "when Encoding.default_internal is nil" do
@@ -48,8 +48,8 @@
     end
 
     it "raises a RangeError is self is greater than 255" do
-      -> { 256.chr }.should raise_error(RangeError)
-      -> { bignum_value.chr }.should raise_error(RangeError)
+      -> { 256.chr }.should raise_error(RangeError, /256 out of char range/)
+      -> { bignum_value.chr }.should raise_error(RangeError, /bignum out of char range/)
     end
   end
 
@@ -137,7 +137,7 @@
           [620,    "TIS-620"]
         ].each do |integer, encoding_name|
           Encoding.default_internal = Encoding.find(encoding_name)
-          -> { integer.chr }.should raise_error(RangeError)
+          -> { integer.chr }.should raise_error(RangeError, /(invalid codepoint|out of char range)/)
         end
       end
     end
@@ -165,12 +165,12 @@
 
   # http://redmine.ruby-lang.org/issues/4869
   it "raises a RangeError is self is less than 0" do
-    -> { -1.chr(Encoding::UTF_8) }.should raise_error(RangeError)
-    -> { (-bignum_value).chr(Encoding::EUC_JP) }.should raise_error(RangeError)
+    -> { -1.chr(Encoding::UTF_8) }.should raise_error(RangeError, /-1 out of char range/)
+    -> { (-bignum_value).chr(Encoding::EUC_JP) }.should raise_error(RangeError, /bignum out of char range/)
   end
 
   it "raises a RangeError if self is too large" do
-    -> { 2206368128.chr(Encoding::UTF_8) }.should raise_error(RangeError)
+    -> { 2206368128.chr(Encoding::UTF_8) }.should raise_error(RangeError, /2206368128 out of char range/)
   end
 
   it "returns a String with the specified encoding" do