Build every ECPG library with -DFRONTEND.

Each of the libraries incorporates src/port files, which often check
FRONTEND.  Build systems disagreed on whether to build libpgtypes this
way.  Only libecpg incorporates files that rely on it today.  Back-patch
to 9.0 (all supported versions) to forestall surprises.

src/interfaces/ecpg/compatlib/Makefile

@@ -18,7 +18,7 @@ SO_MAJOR_VERSION= 3
 SO_MINOR_VERSION= 3
 
 override CPPFLAGS := -I../include -I$(top_srcdir)/src/interfaces/ecpg/include \
-	-I$(libpq_srcdir) -I$(top_srcdir)/src/include/utils $(CPPFLAGS)
+	-I$(libpq_srcdir) -I$(top_srcdir)/src/include/utils -DFRONTEND $(CPPFLAGS)
 override CFLAGS += $(PTHREAD_CFLAGS)
 
 SHLIB_LINK = -L../ecpglib -lecpg -L../pgtypeslib -lpgtypes $(libpq) \

src/interfaces/ecpg/pgtypeslib/Makefile

@@ -18,7 +18,7 @@ SO_MAJOR_VERSION= 3
 SO_MINOR_VERSION= 2
 
 override CPPFLAGS := -I../include -I$(top_srcdir)/src/interfaces/ecpg/include \
-	-I$(top_srcdir)/src/include/utils -I$(libpq_srcdir) $(CPPFLAGS)
+	-I$(top_srcdir)/src/include/utils -I$(libpq_srcdir) -DFRONTEND $(CPPFLAGS)
 override CFLAGS += $(PTHREAD_CFLAGS)
 
 # Need to recompile any libpgport object files

src/tools/msvc/Mkvcbuild.pm

@@ -249,6 +249,7 @@ sub mkvcbuild
 
     my $libecpgcompat =
       $solution->AddProject('libecpg_compat','dll','interfaces','src\interfaces\ecpg\compatlib');
+    $libecpgcompat->AddDefine('FRONTEND');
     $libecpgcompat->AddIncludeDir('src\interfaces\ecpg\include');
     $libecpgcompat->AddIncludeDir('src\interfaces\libpq');
     $libecpgcompat->UseDef('src\interfaces\ecpg\compatlib\compatlib.def');