[crankshaft] Fix DoDeferredMathAbsTaggedHeapNumber overwriting the context with some temporary valu…

src/crankshaft/x87/lithium-codegen-x87.cc

Index: src/crankshaft/x87/lithium-codegen-x87.cc
diff --git a/src/crankshaft/x87/lithium-codegen-x87.cc b/src/crankshaft/x87/lithium-codegen-x87.cc
index fe39fbf8e57c88eb1415f8ec142578e1bd1681b5..4731581fdfd75fedb238aaf0a16361ee6b0703f9 100644
--- a/src/crankshaft/x87/lithium-codegen-x87.cc
+++ b/src/crankshaft/x87/lithium-codegen-x87.cc
@@ -3351,6 +3351,17 @@ void LCodeGen::DoDeferredMathAbsTaggedHeapNumber(LMathAbs* instr) {
   Register tmp = input_reg.is(eax) ? ecx : eax;
   Register tmp2 = tmp.is(ecx) ? edx : input_reg.is(ecx) ? edx : ecx;
 
+  // Make sure that the context isn't overwritten in the AllocateHeapNumber
+  // macro below.
+  if (instr->context()->IsRegister()) {
+    Register context_reg = ToRegister(instr->context());
+    if (tmp.is(context_reg)) {
+      tmp = ebx;
+    } else if (tmp2.is(context_reg)) {
+      tmp2 = ebx;
+    }
+  }
+
   // Preserve the value of all registers.
   PushSafepointRegistersScope scope(this);