sys: add conf/std.debug, generic debugging options

The new sys/conf/std.debug contains the list of debugging options
enabled by default in -CURRENT, so they don't need to be listed
individually in every kernel config.

Introduce *-DEBUG variants of the major kernel configs.

(cherry picked and modified from commit 4f8f9d708e)

Reviewed by:	markj, imp, olce (previous version)
Sponsored by:	Rubicon Communications, LLC ("Netgate")
Differential Revision:	https://reviews.freebsd.org/D46871

sys/amd64/conf/GENERIC-DEBUG

@@ -0,0 +1,9 @@
+#
+# GENERIC-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/amd64
+#
+
+include GENERIC
+include "std.debug"
+
+ident   GENERIC-DEBUG

sys/amd64/conf/MINIMAL-DEBUG

@@ -0,0 +1,9 @@
+#
+# MINIMAL-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/amd64
+#
+
+include MINIMAL
+include "std.debug"
+
+ident   MINIMAL-DEBUG

sys/amd64/conf/NOTES

@@ -153,3 +153,14 @@ options 	KSTACK_PAGES=5
 # Enable detailed accounting by the PV entry allocator.
 
 options 	PV_STATS
+
+#####################################################################
+# Kernel sanitizers
+
+#options	COVERAGE		# Generic kernel coverage. Used by KCOV
+#options	KCOV			# Kernel Coverage Sanitizer
+# Warning: KUBSAN can result in a kernel too large for loader to load
+#options	KUBSAN			# Kernel Undefined Behavior Sanitizer
+#options	KCSAN			# Kernel Concurrency Sanitizer
+#options	KASAN			# Kernel Address Sanitizer
+#options	KMSAN			# Kernel Memory Sanitizer

sys/arm/conf/GENERIC-DEBUG

@@ -0,0 +1,9 @@
+#
+# GENERIC-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/ARMv6
+#
+
+include GENERIC
+include "std.debug"
+
+ident   GENERIC-DEBUG

sys/arm64/conf/GENERIC-DEBUG

@@ -0,0 +1,9 @@
+#
+# GENERIC-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/arm64
+#
+
+include GENERIC
+include "std.debug"
+
+ident   GENERIC-DEBUG

sys/conf/std.debug

@@ -0,0 +1,29 @@
+#
+# std.debug -- Enable debug options for -CURRENT.
+#
+
+options 	BUF_TRACKING		# Track buffer history
+#options	FULL_BUF_TRACKING	# Track more buffer history
+options 	DDB			# Support DDB.
+options 	FULL_BUF_TRACKING	# Track more buffer history
+options 	GDB			# Support remote GDB.
+options 	DEADLKRES		# Enable the deadlock resolver
+options 	INVARIANTS		# Enable calls of extra sanity checking
+options 	INVARIANT_SUPPORT	# Extra sanity checks of internal structures, required by INVARIANTS
+options 	QUEUE_MACRO_DEBUG_TRASH	# Trash queue(2) internal pointers on invalidation
+options 	WITNESS			# Enable checks to detect deadlocks and cycles
+options 	WITNESS_SKIPSPIN	# Don't run witness on spinlocks for speed
+options 	MALLOC_DEBUG_MAXZONES=8	# Separate malloc(9) zones
+options 	VERBOSE_SYSINIT=0	# Support debug.verbose_sysinit, off by default
+options		ALT_BREAK_TO_DEBUGGER	# Enter debugger on keyboard escape sequence
+#options	DEBUG_VFS_LOCKS
+
+# Net80211 debugging
+options		IEEE80211_DEBUG
+
+# USB debugging
+options		USB_DEBUG
+options		HID_DEBUG
+
+# CAM debugging
+options		CAMDEBUG

sys/i386/conf/GENERIC-DEBUG

@@ -0,0 +1,9 @@
+#
+# GENERIC-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/i386
+#
+
+include GENERIC
+include "std.debug"
+
+ident   GENERIC-DEBUG

sys/powerpc/conf/GENERIC-DEBUG

@@ -0,0 +1,9 @@
+#
+# GENERIC-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/powerpc
+#
+
+include GENERIC
+include "std.debug"
+
+ident   GENERIC-DEBUG

sys/powerpc/conf/GENERIC64-DEBUG

@@ -0,0 +1,9 @@
+#
+# GENERIC-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/powerpc64
+#
+
+include GENERIC64
+include "std.debug"
+
+ident   GENERIC64-DEBUG

sys/powerpc/conf/GENERIC64LE-DEBUG

@@ -0,0 +1,9 @@
+#
+# GENERIC-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/powerpc64le
+#
+
+include GENERIC64LE
+include "std.debug"
+
+ident   GENERIC64LE-DEBUG

sys/riscv/conf/GENERIC-DEBUG

@@ -0,0 +1,9 @@
+#
+# GENERIC-DEBUG -- WITNESS and INVARIANTS enabled kernel configuration file
+#			       for FreeBSD/RISC-V
+#
+
+include GENERIC
+include "std.debug"
+
+ident   GENERIC-DEBUG