Fix Decimal speed issue;  backport of r82652 from release27-maint.
diff --git a/Misc/NEWS b/Misc/NEWS
index d1a5dbe..70f8853 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -81,6 +81,10 @@
 Library
 -------
 
+- Fix extreme speed issue in Decimal.pow when the base is an exact
+  power of 10 and the exponent is tiny (for example,
+  Decimal(10) ** Decimal('1e-999999999')).
+
 - Issue #9130: Fix validation of relative imports in parser module.
 
 - Issue #9128: Fix validation of class decorators in parser module.