toolchain/53073: X11 server in HEAD-LLVM build seg faults on execution

[venture37%geeklan.co.uk@localhost]

>Number:         53073
>Category:       toolchain
>Synopsis:       X11 server in HEAD-LLVM build seg faults on execution
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    toolchain-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 04 17:05:00 +0000 2018
>Originator:     Sevan Janiyan
>Release:        NetBSD 8.99.12 201803022030Z
>Organization:
>Environment:
NetBSD 8.99.12 i386 i386
>Description:
On a fresh install of i386 build from HEAD-LLVM it is not possible to start X11. This is not an issue on the stock GCC builds.

[   107.940] (II) intel: Driver for Intel(R) Integrated Graphics Chipsets:
	i810, i810-dc100, i810e, i815, i830M, 845G, 854, 852GM/855GM, 865G,
	915G, E7221 (i915), 915GM, 945G, 945GM, 945GME, Pineview GM,
	Pineview G, 965G, G35, 965Q, 946GZ, 965GM, 965GME/GLE, G33, Q35, Q33,
	GM45, 4 Series, G45/G43, Q45/Q43, G41, B43
[   107.941] (II) intel: Driver for Intel(R) HD Graphics: 2000-6000
[   107.941] (II) intel: Driver for Intel(R) Iris(TM) Graphics: 5100, 6100
[   107.941] (II) intel: Driver for Intel(R) Iris(TM) Pro Graphics: 5200, 6200, P6300
[   107.941] (II) VESA: driver for VESA chipsets: vesa
[   107.941] (--) Using wscons driver on /dev/ttyE4 in pcvt compatibility mode (version 3.32)
[   107.941] (--) using VT number 5
[   107.946] (II) intel(0): Using Kernel Mode Setting driver: i915, version 1.6.0 20080730
[   107.947] (WW) Falling back to old probe method for vesa
[   107.948] (WW) VGA arbiter: cannot open kernel arbiter, no multi-card support
[   107.948] (--) intel(0): Integrated Graphics Chipset: Intel(R) 945GM
[   107.948] (--) intel(0): CPU: x86, sse2, sse3
[   107.948] (II) intel(0): Creating default Display subsection in Screen section
	"Builtin Default intel Screen 0" for depth/fbbpp 24/32
[   107.948] (==) intel(0): Depth 24, (--) framebuffer bpp 32
[   107.948] (==) intel(0): RGB weight 888
[   107.948] (==) intel(0): Default visual is TrueColor
[   107.953] (II) intel(0): Output LVDS1 has no monitor section
[   107.953] (II) intel(0): Enabled output LVDS1
[   107.953] (II) intel(0): Output VGA1 has no monitor section
[   107.953] (II) intel(0): Enabled output VGA1
[   107.953] (--) intel(0): Using a maximum size of 256x256 for hardware cursors
[   107.953] (II) intel(0): Output VIRTUAL1 has no monitor section
[   107.953] (II) intel(0): Enabled output VIRTUAL1
[   107.953] (--) intel(0): Output LVDS1 using initial mode 1024x768 on pipe 1
[   107.953] (==) intel(0): TearFree disabled
[   107.953] (==) intel(0): DPI set to (96, 96)
[   107.953] (II) Loading sub module "dri2"
[   107.953] (II) LoadModule: "dri2"
[   107.953] (II) Module "dri2" already built-in
[   107.953] (II) UnloadModule: "vesa"
[   107.953] (II) Unloading vesa
[   107.954] (==) Depth 24 pixmap format is 32 bpp
[   107.958] (II) intel(0): SNA initialized with Alviso (gen3) backend
[   107.958] (==) intel(0): Backing store enabled
[   107.958] (==) intel(0): Silken mouse enabled
[   107.959] (II) intel(0): HW Cursor enabled
[   107.959] (II) intel(0): RandR 1.2 enabled, ignore the following RandR disabled message.
[   107.961] (==) intel(0): DPMS enabled
[   107.963] (II) intel(0): [XvMC] i915_xvmc driver initialized.
[   107.964] (II) intel(0): [DRI2] Setup complete
[   107.964] (II) intel(0): [DRI2]   DRI driver: i915
[   107.964] (II) intel(0): [DRI2]   VDPAU driver: i915
[   107.964] (II) intel(0): direct rendering: DRI2 enabled
[   107.964] (--) RandR disabled
[   108.024] (II) AIGLX: enabled GLX_MESA_copy_sub_buffer
[   108.024] (II) AIGLX: enabled GLX_ARB_create_context
[   108.024] (II) AIGLX: enabled GLX_ARB_create_context_profile
[   108.024] (II) AIGLX: enabled GLX_EXT_create_context_es{,2}_profile
[   108.024] (II) AIGLX: enabled GLX_INTEL_swap_event
[   108.024] (II) AIGLX: enabled GLX_SGI_swap_control and GLX_MESA_swap_control
[   108.024] (II) AIGLX: enabled GLX_EXT_framebuffer_sRGB
[   108.024] (II) AIGLX: enabled GLX_ARB_fbconfig_float
[   108.024] (II) AIGLX: enabled GLX_EXT_fbconfig_packed_float
[   108.024] (II) AIGLX: GLX_EXT_texture_from_pixmap backed by buffer objects
[   108.025] (II) AIGLX: Loaded and initialized i915
[   108.025] (II) GLX: Initialized DRI2 GL provider for screen 0
[   108.038] (EE) Segmentation fault at address 0x4
[   108.038] (EE) 
Fatal server error:
[   108.038] (EE) Caught signal 11 (Segmentation fault). Server aborting
>How-To-Repeat:
Install NetBSD/i386 build from HEAD-LLVM
run startx
>Fix: