RFR: 8326406: Remove mapfile support from makefiles [v2]

[Magnus Ihse Bursie]

> Once [JDK-8017234](https://bugs.openjdk.org/browse/JDK-8017234) is done, we have no need for mapfiles anymore in the JDK project. The mapfile handling was inherited from the old build system and is just messy. We should remove it to make the linking process more clear.
> 
> Note that this PR is [dependent on](https://mail.openjdk.org/pipermail/jdk-dev/2021-March/005232.html) https://github.com/openjdk/jdk/pull/17955.

Magnus Ihse Bursie has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase.

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17982/files
  - new: https://git.openjdk.org/jdk/pull/17982/files/85a076ef..85a076ef

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17982&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17982&range=00-01

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/17982.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17982/head:pull/17982

PR: https://git.openjdk.org/jdk/pull/17982