Internet Download Manager

What's new in this version:

Notable changes:
intl:
- Update ICU to 64.2. This adds support for Japanese Era
- Fixes a bug in ICU that affected Node.js 12.0.0 in the case where new Date().toLocaleString() was called with a non-default locale

C++ API:
- Added an overload EmitAsyncDestroy that can be used during garbage collection

Commits:
- benchmark: fix http bench-parser.js
- bootstrap: delay the instantiation of maps in per-context scripts
- build: allow icu download to use other hashes besides md5
- build: disable custom v8 snapshot by default
- crypto: update root certificates
- deps: backport ICU-20575 to fix err/crasher
- deps: backport ICU-20558 to fix Intl crasher
- deps: update ICU to 64.2
- dgram: change 'this' to 'self' for 'isConnected'
- doc: add Node 12 to the first list of versions
- doc: update comment in bootstrap for primordials
- doc: simplify GOVERNANCE.md text
- doc: fix pull request number
- doc: clarify behaviour of writeFile(fd)
- doc: fix v12.0.0 changelog id
- doc: simplify Collaborator pre-nomination text
- lib: throw a special error in internal/assert
- module: initialize module_wrap.callbackMap during pre-execution
- (SEMVER-MINOR) n-api: do not require JS Context for napi_async_destroy()
- process: reduce the number of internal frames in async stack trace
- report: print common items first for readability
- src: refactor deprecated UVException in node_file.cc
- src: move OnMessage to node_errors.cc
- src: use predefined AliasedBuffer types in the code base
- src: apply clang-tidy modernize-deprecated-headers found by Jenkins CI
- (SEMVER-MINOR) src: do not require JS Context for ~AsyncResoure()
- (SEMVER-MINOR) src: add Environment overload of EmitAsyncDestroy
- src: apply clang-tidy rule modernize-use-equals-default
- src: use std::vector<size_t> instead of IndexArray
- src: enable context snapshot after running per-context scripts
- src: enable snapshot with per-isolate data
- src: implement IsolateData serialization and deserialization
- src: allow creating NodeMainInstance that does not own the isolate
- test: refactor net-connect-handle-econnrefused
- test: move test-net-connect-handle-econnrefused
- test: rework to remove flakiness, and be parallel
- test: fix ineffective error tests
- test: make test-worker-esm-missing-main more robust
- test: increase coverage in lib/internal/dns/promises.js
- tls: include invalid method name in thrown error
- tools: update certdata.txt
- tools: update LICENSE and tools/icu/current_ver.dep
- tools: fix use-after-free mkcodecache warning
- tools: update tools/license-builder.sh
- tools: implement node_mksnapshot
- util: add prototype support for boxed primitives
- util: rename setIteratorBraces to getIteratorBraces
- util: improve Symbol.toStringTag handling