pgsql: Add PGTYPESchar_free() to avoid cross-module problems on Windows

Add PGTYPESchar_free() to avoid cross-module problems on Windows.

On Windows, it is sometimes important for corresponding malloc() and
free() calls to be made from the same DLL, since some build options can
result in multiple allocators being active at the same time. For that
reason we already provided PQfreemem(). This commit adds a similar
function for freeing string results allocated by the pgtypes library.

Author: Takayuki Tsunakawa
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1F8AD5D6%40G01JPEXMBYT05

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4c8156d87108fa1f245bee13775e76819cd46a90

Modified Files
--------------
doc/src/sgml/ecpg.sgml | 18 ++++-
src/interfaces/ecpg/include/Makefile | 2 +-
src/interfaces/ecpg/include/pgtypes.h | 17 +++++
src/interfaces/ecpg/include/pgtypes_date.h | 1 +
src/interfaces/ecpg/include/pgtypes_interval.h | 1 +
src/interfaces/ecpg/include/pgtypes_numeric.h | 2 +
src/interfaces/ecpg/include/pgtypes_timestamp.h | 1 +
src/interfaces/ecpg/pgtypeslib/common.c | 10 +++
src/interfaces/ecpg/pgtypeslib/exports.txt | 1 +
.../ecpg/test/expected/pgtypeslib-dt_test.c | 84 +++++++++++-----------
.../ecpg/test/expected/pgtypeslib-dt_test2.c | 12 ++--
.../ecpg/test/expected/pgtypeslib-num_test.c | 10 +--
.../ecpg/test/expected/pgtypeslib-num_test2.c | 26 +++----
.../ecpg/test/expected/preproc-outofscope.c | 2 +
src/interfaces/ecpg/test/expected/sql-sqlda.c | 4 +-
src/interfaces/ecpg/test/pgtypeslib/dt_test.pgc | 84 +++++++++++-----------
src/interfaces/ecpg/test/pgtypeslib/dt_test2.pgc | 12 ++--
src/interfaces/ecpg/test/pgtypeslib/num_test.pgc | 10 +--
src/interfaces/ecpg/test/pgtypeslib/num_test2.pgc | 26 +++----
src/interfaces/ecpg/test/sql/sqlda.pgc | 2 +-
20 files changed, 189 insertions(+), 136 deletions(-)