[MERGE #5885 @rhuanjl] Implement stage 3 proposal globalThis

Merge pull request #5885 from rhuanjl:globalThis

This PR implements the stage 3 proposal globalThis.

1. Actual implementation is 2 lines of code
2. I've added a default enabled flag so it can be flagged off if ever necessary
3. I've added a few tests which I think should be sufficient
4. The large size of the diff is only due to it needing a byte code regen

cc: @ljharb @pleath

closes: #1658

Author: boingoing

bin/ch/DbgController.js

@@ -62,6 +62,7 @@ var controllerObj = (function () {
         // Discard all known globals to reduce baseline noise.
         [
             "#__proto__",
+            "globalThis",
             "Array",
             "ArrayBuffer",
             "Atomics",

lib/Common/ConfigFlagsList.h

@@ -655,9 +655,10 @@ PHASE(All)
 #define DEFAULT_CONFIG_ES6UnicodeVerbose       (true)
 #define DEFAULT_CONFIG_ES6Unscopables          (true)
 #define DEFAULT_CONFIG_ES6RegExSticky          (true)
-#define DEFAULT_CONFIG_ES2018RegExDotAll          (true)
-#define DEFAULT_CONFIG_ESBigInt          (false)
+#define DEFAULT_CONFIG_ES2018RegExDotAll       (true)
+#define DEFAULT_CONFIG_ESBigInt                (false)
 #define DEFAULT_CONFIG_ESSymbolDescription     (true)
+#define DEFAULT_CONFIG_ESGlobalThis            (true)
 #ifdef COMPILE_DISABLE_ES6RegExPrototypeProperties
     // If ES6RegExPrototypeProperties needs to be disabled by compile flag, DEFAULT_CONFIG_ES6RegExPrototypeProperties should be false
     #define DEFAULT_CONFIG_ES6RegExPrototypeProperties (false)
@@ -1195,6 +1196,9 @@ FLAGR(Boolean, ESBigInt, "Enable ESBigInt flag", DEFAULT_CONFIG_ESBigInt)
 // ES Symbol.prototype.description flag
 FLAGR(Boolean, ESSymbolDescription, "Enable Symbol.prototype.description", DEFAULT_CONFIG_ESSymbolDescription)
 
+//ES globalThis flag
+FLAGR(Boolean, ESGlobalThis, "Enable globalThis", DEFAULT_CONFIG_ESGlobalThis)
+
 // This flag to be removed once JITing generator functions is stable
 FLAGNR(Boolean, JitES6Generators        , "Enable JITing of ES6 generators", false)
 

lib/Runtime/Base/JnDirectFields.h

@@ -424,6 +424,7 @@ ENTRY(defineProperties)
 ENTRY(toGMTString)
 ENTRY(compile)
 ENTRY(global)
+ENTRY(globalThis)
 ENTRY(lastIndex)
 ENTRY(multiline)
 ENTRY(dotAll)

lib/Runtime/Base/ThreadConfigFlagsList.h

@@ -50,6 +50,7 @@ FLAG_RELEASE(IsESDynamicImportEnabled, ESDynamicImport)
 FLAG_RELEASE(IsESBigIntEnabled, ESBigInt)
 FLAG_RELEASE(IsESExportNsAsEnabled, ESExportNsAs)
 FLAG_RELEASE(IsESSymbolDescriptionEnabled, ESSymbolDescription)
+FLAG_RELEASE(IsESGlobalThisEnabled, ESGlobalThis)
 #ifdef ENABLE_PROJECTION
 FLAG(AreWinRTDelegatesInterfaces, WinRTDelegateInterfaces)
 FLAG_RELEASE(IsWinRTAdaptiveAppsEnabled, WinRTAdaptiveApps)

lib/Runtime/ByteCode/ByteCodeCacheReleaseFileVersion.h

@@ -4,6 +4,6 @@
 //-------------------------------------------------------------------------------------------------------
 // NOTE: If there is a merge conflict the correct fix is to make a new GUID.
 
-// {E4B5202C-0ACB-48C6-A96F-8A4A29848ED0}
+// {11BA1CDD-86FC-4489-95EB-355A78E78EF8}
 const GUID byteCodeCacheReleaseFileVersion =
-{ 0xE4B5202C, 0x0ACB, 0x48C6, { 0xA9, 0x6F, 0x8A, 0x4A, 0x29, 0x84, 0x8E, 0xD0 } };
+{ 0x11ba1cdd, 0x86fc, 0x4489, { 0x95, 0xeb, 0x35, 0x5a, 0x78, 0xe7, 0x8e, 0xf8 } };

lib/Runtime/Library/InJavascript/Intl.js.bc.32b.h

@@ -1277,6 +1277,10 @@ namespace Js
         randSeed0 = 0;
         randSeed1 = 0;
 
+        if (globalObject->GetScriptContext()->GetConfig()->IsESGlobalThisEnabled())
+        {
+            AddMember(globalObject, PropertyIds::globalThis, globalObject, PropertyConfigurable | PropertyWritable);
+        }
         AddMember(globalObject, PropertyIds::NaN, nan, PropertyNone);
         AddMember(globalObject, PropertyIds::Infinity, positiveInfinite, PropertyNone);
         AddMember(globalObject, PropertyIds::undefined, undefinedValue, PropertyNone);