Bug#882490: gcc: Tune default --param ggc-min-expand for 32-bit arches

[Mathieu Malaterre <malat@debian.org>]

Control: forwarded -1 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78971

Here is the current state for compiling webkit on mipsel (1)

# Lower memory requirements on architectures with only 2 GB address space
ifneq (,$(filter $(DEB_HOST_ARCH),mips mipsel sh4))
CFLAGS := $(CFLAGS:-g1=-g0)
CFLAGS := $(CFLAGS:-O2=-Os)
CPPFLAGS += --param ggc-min-expand=10
EXTRA_CMAKE_ARGUMENTS += -DENABLE_UNIFIED_BUILDS=OFF
endif

Same goes for openvdb (2)

ifneq (,$(filter $(DEB_HOST_ARCH), mipsel))
  # smaller debug packages:
  CXXFLAGS := $(CXXFLAGS:-g=-g0)
  CXXFLAGS := $(CXXFLAGS:-O2=-O0)
  DEB_CXXFLAGS_MAINT_APPEND += --param ggc-min-expand=10
  # makes linking slower, so it shouldn't be enabled when not needed:
  DEB_LDFLAGS_MAINT_APPEND += -Wl,--no-keep-memory -Wl,--reduce-memory-overhead



(1) https://salsa.debian.org/webkit-team/webkit/-/blob/debian/2.39.1-1/debian/rules#L66
(2) https://salsa.debian.org/multimedia-team/openvdb/-/blob/debian/10.0.0-11/debian/rules#L28-34