RFR: 8260043: Reduce allocation in sun.net.www.protocol.jar.Handler.parseURL [v4]

[Eirik Bjorsnos]

> By moving string splitting and concatenation into the canonizeString utility, we can defer allocation until we determine that canonization is required. This saves two string allocations and a string concat for the common case where canonization is not required.
> 
> As a refactoring, move ParseUtil.canonizeString/doCanonize into Handler since that's the only call site.
> 
> Finally, let's rename the method to canonizalizeString, since canonization is an rather unrelated term.

Eirik Bjorsnos has updated the pull request incrementally with one additional commit since the last revision:

  Update copyright year in affected files since the change is non-trivial

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2167/files
  - new: https://git.openjdk.java.net/jdk/pull/2167/files/0be597b1..7bde5f15

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2167&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2167&range=02-03

  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2167.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2167/head:pull/2167

PR: https://git.openjdk.java.net/jdk/pull/2167