ART: Move overflow gap definition to art.go

Move the stack overflow guard page size definitions into art.go. This
is in preparation for conditional increases necessary for instrumented
builds, as there is no bp support.

Bug: 31098551
Test: m test-art-host
Change-Id: I6d8364ea60c624a89790e9a936dfe7447ad41487
diff --git a/build/art.go b/build/art.go
index 61a9759..6dca793 100644
--- a/build/art.go
+++ b/build/art.go
@@ -76,6 +76,14 @@
 		asflags = append(asflags, "-DART_USE_OLD_ARM_BACKEND=1")
 	}
 
+	cflags = append(cflags,
+			"-DART_STACK_OVERFLOW_GAP_arm=8192",
+			"-DART_STACK_OVERFLOW_GAP_arm64=8192",
+			"-DART_STACK_OVERFLOW_GAP_mips=16384",
+			"-DART_STACK_OVERFLOW_GAP_mips64=16384",
+			"-DART_STACK_OVERFLOW_GAP_x86=8192",
+			"-DART_STACK_OVERFLOW_GAP_x86_64=8192")
+
 	return cflags, asflags
 }