Only complain about BigInt literals in pre-ESNext targets.

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -30528,13 +30528,10 @@ namespace ts {
                 isPrefixUnaryExpression(node.parent) && isLiteralTypeNode(node.parent.parent);
             if (!literalType) {
                 if (languageVersion < ScriptTarget.ESNext) {
-                    if (grammarErrorOnNode(node, Diagnostics.BigInt_literals_are_not_available_when_targetting_lower_than_ESNext)) {
+                    if (grammarErrorOnNode(node, Diagnostics.BigInt_literals_are_not_available_when_targeting_lower_than_ESNext)) {
                         return true;
                     }
                 }
-                if (!compilerOptions.experimentalBigInt) {
-                    return grammarErrorOnNode(node, Diagnostics.Experimental_support_for_BigInt_is_a_feature_that_is_subject_to_change_in_a_future_release_Set_the_experimentalBigInt_option_to_remove_this_warning);
-                }
             }
             return false;
         }

src/compiler/commandLineParser.ts

@@ -584,12 +584,6 @@ namespace ts {
             category: Diagnostics.Experimental_Options,
             description: Diagnostics.Enables_experimental_support_for_emitting_type_metadata_for_decorators
         },
-        {
-            name: "experimentalBigInt",
-            type: "boolean",
-            category: Diagnostics.Experimental_Options,
-            description: Diagnostics.Enables_experimental_support_for_ESNext_BigInt_literals
-        },
 
         // Advanced
         {

src/compiler/diagnosticMessages.json

@@ -1011,10 +1011,6 @@
         "category": "Message",
         "code": 1350
     },
-    "Experimental support for BigInt is a feature that is subject to change in a future release. Set the 'experimentalBigInt' option to remove this warning.": {
-        "category": "Error",
-        "code": 1351
-    },
 
     "Duplicate identifier '{0}'.": {
         "category": "Error",
@@ -2505,7 +2501,7 @@
         "category": "Error",
         "code": 2736
     },
-    "BigInt literals are not available when targetting lower than ESNext.": {
+    "BigInt literals are not available when targeting lower than ESNext.": {
         "category": "Error",
         "code": 2737
     },
@@ -3921,10 +3917,6 @@
         "category": "Error",
         "code": 6370
     },
-    "Enables experimental support for ESNext BigInt literals.": {
-        "category": "Message",
-        "code": 6371
-    },
 
     "The expected type comes from property '{0}' which is declared here on type '{1}'": {
         "category": "Message",

src/compiler/types.ts

@@ -4495,7 +4495,6 @@ namespace ts {
         downlevelIteration?: boolean;
         emitBOM?: boolean;
         emitDecoratorMetadata?: boolean;
-        experimentalBigInt?: boolean;
         experimentalDecorators?: boolean;
         forceConsistentCasingInFileNames?: boolean;
         /*@internal*/help?: boolean;