Bug 1526840 - Adapt ToBoolean Ion type inference for false BigInt values r=jandem

Differential Revision: https://phabricator.services.mozilla.com/D19477

--HG--
extra : moz-landing-system : lando

js/src/jit-test/tests/ion/bug1526840.js

@@ -0,0 +1,12 @@
+
+setJitCompilerOption("offthread-compilation.enable", 0);
+setJitCompilerOption("ion.warmup.trigger", 0);
+
+for (let j = 0; j < 2; ++j) {
+    let z = j ? 0n : 1;
+    if (z) {
+        z = 0;
+    } else {
+        z = 0;
+    }
+}

js/src/jit/IonBuilder.cpp

@@ -2805,7 +2805,13 @@ AbortReasonOr<Ok> IonBuilder::improveTypesAtTypeOfCompare(MCompare* ins,
     filter.addType(TypeSet::StringType(), alloc_->lifoAlloc());
   } else if (constant->toString() == TypeName(JSTYPE_SYMBOL, names)) {
     filter.addType(TypeSet::SymbolType(), alloc_->lifoAlloc());
-  } else if (constant->toString() == TypeName(JSTYPE_OBJECT, names)) {
+  }
+#ifdef ENABLE_BIGINT
+  else if (constant->toString() == TypeName(JSTYPE_BIGINT, names)) {
+    filter.addType(TypeSet::BigIntType(), alloc_->lifoAlloc());
+  }
+#endif
+  else if (constant->toString() == TypeName(JSTYPE_OBJECT, names)) {
     filter.addType(TypeSet::NullType(), alloc_->lifoAlloc());
     if (trueBranch) {
       filter.addType(TypeSet::AnyObjectType(), alloc_->lifoAlloc());
@@ -3049,6 +3055,10 @@ AbortReasonOr<Ok> IonBuilder::improveTypesAtTest(MDefinition* ins,
                  alloc_->lifoAlloc());  // ToBoolean(0.0) == false
     base.addType(TypeSet::StringType(),
                  alloc_->lifoAlloc());  // ToBoolean("") == false
+#ifdef ENABLE_BIGINT
+    base.addType(TypeSet::BigIntType(),
+                 alloc_->lifoAlloc());  // ToBoolean(0n) == false
+#endif
 
     // If the typeset does emulate undefined, then we cannot filter out
     // objects.

js/src/jit/MIR.cpp

@@ -6206,7 +6206,11 @@ static bool TryAddTypeBarrierForWrite(TempAllocator& alloc,
     case MIRType::Int32:
     case MIRType::Double:
     case MIRType::String:
-    case MIRType::Symbol: {
+    case MIRType::Symbol:
+#ifdef ENABLE_BIGINT
+    case MIRType::BigInt:
+#endif
+    {
       // The property is a particular primitive type, guard by unboxing the
       // value before the write.
       if (!(*pvalue)->mightBeType(propertyType)) {