pgsql: Clarify the regexp used to detect source files in MSVC builds.

Clarify the regexp used to detect source files in MSVC builds.

The old pattern would match files with strange extensions like *.ry or
*.lpp. Refactor it to only include files with known extensions, and to make
it more readable.

Per Andrew Dunstan's suggestion.

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/ce01548d4fdbc06dce59f90a3e4598162b1e8ea1

Modified Files
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src/tools/msvc/MSBuildProject.pm |    2 +-
src/tools/msvc/VCBuildProject.pm |    2 +-
2 files changed, 2 insertions(+), 2 deletions(-)