Re: Row pattern recognition

Attached is the v5 patch. Differences from previous patch include:

* Resolve complaint from "PostgreSQL Patch Tester"
https://commitfest.postgresql.org/44/4460/

- Change gram.y to use PATTERN_P instead of PATTERN. Using PATTERN seems
to make trouble with Visual Studio build.

:
:
[10:07:57.853] FAILED: src/backend/parser/parser.a.p/meson-generated_.._gram.c.obj
[10:07:57.853] "cl" "-Isrc\backend\parser\parser.a.p" "-Isrc\backend\parser" "-I..\src\backend\parser" "-Isrc\include" "-I..\src\include" "-Ic:\openssl\1.1\include" "-I..\src\include\port\win32" "-I..\src\include\port\win32_msvc" "/MDd" "/nologo" "/showIncludes" "/utf-8" "/W2" "/Od" "/Zi" "/DWIN32" "/DWINDOWS" "/D__WINDOWS__" "/D__WIN32__" "/D_CRT_SECURE_NO_DEPRECATE" "/D_CRT_NONSTDC_NO_DEPRECATE" "/wd4018" "/wd4244" "/wd4273" "/wd4101" "/wd4102" "/wd4090" "/wd4267" "-DBUILDING_DLL" "/Fdsrc\backend\parser\parser.a.p\meson-generated_.._gram.c.pdb" /Fosrc/backend/parser/parser.a.p/meson-generated_.._gram.c.obj "/c" src/backend/parser/gram.c
[10:07:57.860] c:\cirrus\build\src\backend\parser\gram.h(379): error C2365: 'PATTERN': redefinition; previous definition was 'typedef'
[10:07:57.860] C:\Program Files (x86)\Windows Kits\10\include\10.0.20348.0\um\wingdi.h(1375): note: see declaration of 'PATTERN'
[10:07:57.860] c:\cirrus\build\src\backend\parser\gram.h(379): error C2086: 'yytokentype PATTERN': redefinition
[10:07:57.860] c:\cirrus\build\src\backend\parser\gram.h(379): note: see declaration of 'PATTERN'
[10:07:57.860] ninja: build stopped: subcommand failed.

* Resolve complaint from "make headerscheck"

- Change Windowapi.h and nodeWindowAgg.c to remove unecessary extern
and public functions.

Best reagards,
--
Tatsuo Ishii
SRA OSS LLC
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp