[cleanup] remove unused Destructuring Assignment bailout reason

BUG=v8:811
LOG=N
R=adamk@chromium.org

Review URL: https://codereview.chromium.org/1504553003

Cr-Commit-Position: refs/heads/master@{#32663}

src/bailout-reason.h

@@ -21,7 +21,6 @@ namespace internal {
     "Arguments object value in a test context")                                \
   V(kArrayBoilerplateCreationFailed, "Array boilerplate creation failed")      \
   V(kArrayIndexConstantValueTooBig, "Array index constant value too big")      \
-  V(kAssignmentPattern, "Destructuring assignment")                            \
   V(kAssignmentToArguments, "Assignment to arguments")                         \
   V(kAssignmentToLetVariableBeforeInitialization,                              \
     "Assignment to let variable before initialization")                        \