Bump allowed stack frame size for unit tests/host programs

We tend to have a lot more things inlined when building unit tests,
so let's just up the -Wframe-larger-than to avoid hitting it.

This time, it was noticed in travis-ci with the ubuntu:latest
image.

Signed-off-by: Stewart Smith <stewart@linux.ibm.com>

Makefile.main

@@ -30,7 +30,6 @@ CWARNS := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 	  -Wmissing-prototypes -Wmissing-declarations \
 	  -Wwrite-strings -Wcast-align \
 	  -Winit-self \
-	  -Wframe-larger-than=1024 \
 	  $(call try-cflag,$(CC),--Wno-stringop-truncation) \
 	  -Werror
 
@@ -45,6 +44,12 @@ HOSTCFLAGS += $(call try-cflag,$(HOSTCC),-Wjump-misses-init) \
 	  $(call try-cflag,$(HOSTCC),-Wsuggest-attribute=noreturn)
 HOSTCFLAGS += -DDEBUG -DCCAN_LIST_DEBUG
 
+# We want small stack usage for skiboot
+# but host compilation of unit tests tend to inline heavily,
+# which creates larger stack frames and triggering useless warnings
+HOSTCFLAGS += -Wframe-larger-than=4096
+CWARNS += -Wframe-larger-than=1024
+
 HOSTGCOVCFLAGS = -fprofile-arcs -ftest-coverage -lgcov -O0 -g -pg
 
 VALGRIND := valgrind -q --show-reachable=yes --error-exitcode=99