pgsql: Replace backslashes by forward slashes in MSVC build code

Replace backslashes by forward slashes in MSVC build code

This makes it possible to run some stages of these build scripts on
non-Windows systems.  That way, we can more easily test whether file
moves or makefile changes might break the MSVC build.

Peter Eisentraut and Michael Paquier

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/854adb83711da8fda2a8f028c27ad8956179c04a

Modified Files
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src/tools/msvc/MSBuildProject.pm |    2 +-
src/tools/msvc/Mkvcbuild.pm      |  344 +++++++++++++++++++-------------------
src/tools/msvc/Project.pm        |   42 +++--
src/tools/msvc/Solution.pm       |  138 +++++++--------
4 files changed, 262 insertions(+), 264 deletions(-)