Don't leak memory on failure in uvm_pglistalloc_contig.

Free pages like uvm_pglistalloc_simple does.

Discovered by code inspection.
Tag all 0600 files as "nodiff" (== secret).
Back out previous silliness -- on failure no pages are allocated.
When completing a FP trap, only load the FPU if we don't already own it.
While the FPU is on, disable kernel preemption.
Update PCU_REENABLE for MP.  For UP, add a KASSERT to make sure it's never
present.
Build fix for when there is no gpio in the kernel.

PR/48816: Compile fix for src/sys/arch/arm/broadcom/bcm2835_gpio.c
Document external directories
Document MKDEBUG and MKDEBUGLIB
Document MKCROSSGDB, MKKDEBUG and build.sh kernel.gdb=
Use the scratch page, not zero, to clear ggtt entries for gen<6.
Use correct value for gtt->gtt_bsh in agp case (unused, so harmless).
Fix page/byte sense of AGP GTT parameter calculations.
Remove (bad) debugging message that crept into i915_gem_gtt_init.
Make it compile without options DIAGNOSTIC by removing a variable only set
once and only tested once in an assert.
Create /var/tmp for vi. Pointed out by Izumi Tsutsui.
Move declarations of getdelim() and getline() from the (incorrect) ANSI C
section to POSIX-2008.  From Jarmo Jaakkola in PR standards/48788.
Import compiler-rt r209132. Revert use of TI mode on 32bit PPC.
Factor out some common code (more to be done) from PR/48821
Add ability to have mbufs disappear (to another interface) during
npf_rproc_run().  For upcoming npf_ext_route extension.

Guidance and ok by rmind@.
add npf_ext_param_string()