RFR: 8273616: Fix trivial doc typos in the java.base module [v3]

[Pavel Rappo]

> 8273616: Fix trivial doc typos in the java.base module

Pavel Rappo has updated the pull request incrementally with one additional commit since the last revision:

  Use "ensure" instead of "insure"

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/5475/files
  - new: https://git.openjdk.java.net/jdk/pull/5475/files/9a9deee1..4b33fb94

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=5475&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=5475&range=01-02

  Stats: 3 lines in 2 files changed: 0 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5475.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5475/head:pull/5475

PR: https://git.openjdk.java.net/jdk/pull/5475