Revert "Use -D_GLIBCXX_DEBUG here, too, in a dbgutil build"

It is broken in the same way on iOS as on OS X, they use the same libstdc++.

This reverts commit ca3392e8.

solenv/gbuild/platform/IOS_ARM_GCC.mk

@@ -75,13 +75,6 @@ gb_OBJCFLAGS := -x objective-c $(gb_OBJC_OBJCXX_COMMON_FLAGS)
 gb_COMPILERDEFS += \
 		-DBOOST_DETAIL_NO_CONTAINER_FWD
 
-# enable debug STL
-ifeq ($(gb_ENABLE_DBGUTIL),$(true))
-gb_COMPILERDEFS += \
-	-D_GLIBCXX_DEBUG \
-
-endif
-
 gb_LinkTarget_LDFLAGS := $(SOLARLIB) \
 #man ld says: obsolete	-Wl,-multiply_defined,suppress \