pgsql: Make the includes field an array in MSVC build scripts

Make the includes field an array in MSVC build scripts

Previously the 'includes' field was a string.  It's slightly nicer to
manage this when it's defined as an array instead. This allows us to
more easily detect and eliminate duplicates.

Reviewed-by: Álvaro Herrera, Andrew Dunstan, Dagfinn Ilmari Mannsåker
Discussion: https://postgr.es/m/CAApHDvpo6g5csCTjc_0C7DMvgFPomVb0Rh-AcW5afd=Ya=LRuw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/33d74c5d00e45248df66fa1bcd9222e0713ea5b1

Modified Files
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src/tools/msvc/MSBuildProject.pm |  7 ++-----
src/tools/msvc/Mkvcbuild.pm      |  4 ++--
src/tools/msvc/Project.pm        | 12 +++++++-----
3 files changed, 11 insertions(+), 12 deletions(-)