git: openjdk/jdk: master: 8351029: IncludeCustomExtension does not work on cygwin with source code below /home

[Magnus Ihse Bursie]

Changeset: a091e2f2
Branch: master
Author:    Magnus Ihse Bursie <ihse at openjdk.org>
Date:      2025-05-09 09:10:06 +0000
URL:       https://git.openjdk.org/jdk/commit/a091e2f2810da17ff61a63fd0f1f6538f1bdbb70

8351029: IncludeCustomExtension does not work on cygwin with source code below /home

Reviewed-by: erikj

! make/PreInit.gmk
! make/PreInitSupport.gmk
! make/common/MakeFileStart.gmk
! make/common/MakeIncludeStart.gmk