Fix --enable-pch option on msvc 64bit compiler

When /Zmxxx option is provided to 64 bit compiler it throws on us
weird error messages, no matter what the value is passed.  It was
mentioned in the knowledge base, that removing it entirely fixes
the problem.

Change-Id: I95296ad8811d0065498f0ef55ae503d4a07b914b
Reviewed-on: https://gerrit.libreoffice.org/13779Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Michael Stahl <mstahl@redhat.com>

solenv/gbuild/platform/com_MSC_defs.mk

@@ -153,7 +153,6 @@ gb_CFLAGS := \
 	-wd4706 \
 	-wd4800 \
 	-Zc:wchar_t- \
-	-Zm500 \
 
 gb_CXXFLAGS := \
 	-Gd \
@@ -184,7 +183,6 @@ gb_CXXFLAGS := \
 	-wd4800 \
 	-wd4913 \
 	-Zc:wchar_t- \
-	-Zm500 \
 
 ifneq ($(MSVC_USE_DEBUG_RUNTIME),)
 gb_CXXFLAGS += \
@@ -217,6 +215,14 @@ ifeq ($(CPUNAME),X86_64)
 gb_CXXFLAGS += \
 	-wd4267 \
 
+else
+
+gb_CXXFLAGS += \
+	-Zm500 \
+
+gb_CFLAGS += \
+	-Zm500 \
+
 endif
 
 # rc.exe does not support -nologo in 6.1.6723.1 that is in the Windows SDK 6.0A