RFR: 8292244: Remove unnecessary include directories

[Erik Joelsson]

On Thu, 11 Aug 2022 09:56:29 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

> Remove `java.base:include` from `EXTRA_HEADER_DIRS`.
> 
> The directory contains base versions of the files present in `<build>/support/modules_include/java.base`; the latter is automatically [included in every JDK library build](https://github.com/openjdk/jdk/blob/master/make/autoconf/flags-cflags.m4#L434).
> 
> Verified that:
> - cl.exe command line contains `-I<stuff>/modules_include/java.base`
> - Windows, Linux and Mac builds still pass

Marked as reviewed by erikj (Reviewer).

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PR: https://git.openjdk.org/jdk/pull/9835