System Environment:
--------------------------
Platform: IVB
Libdrm:	(master)libdrm-2.4.56-21-g8c2ae1695913990cbe6c6a8aa294f354eba33bd0
Mesa:	(master)dc0bd799cabdd974b05bd217304944392169fb50
Xserver:(master)xorg-server-1.16.0-152-g3a51418b2db353519a1779cf3cebbcc9afba2520
Xf86_video_intel:(master)2.99.914-94-g908520a7dacade8b6716e7c30549847464a33a81
Libva:	(master)c356638098e55453d2fac8bbb92eafc8cc32d6f4
Libva_intel_driver:(master)812d8d039031bf20e66748a39edcdb8f9c798ec4
Kernel:   (drm-intel-nightly)51c49eafab38a20bdd12344d31d09810c9b0c3f6

Bug detailed description:
---------------------------
It segfault on SNB+ platforms with mesa master or 10.3 branch. It's a new case.

output:
Segmentation fault (core dumped)

(gdb) bt
#0  validate_uniform_parameters (ctx=0x7ffff39d7038, shProg=0xa3d798,
    location=0, count=1, array_index=0x7fffffffdf6c,
    caller=0x7ffff3dc11c0 "glUniform", negative_one_is_not_valid=false)
    at ../../src/mesa/main/uniform_query.cpp:272
#1  0x00007ffff3b4bfa9 in _mesa_uniform (ctx=0x7ffff39d7038, shProg=0xa3d798,
    location=0, count=count@entry=1, values=values@entry=0x7fffffffdfbc,
    type=type@entry=5124) at ../../src/mesa/main/uniform_query.cpp:618
#2  0x00007ffff3b48ba9 in _mesa_Uniform1i (location=<optimized out>, v0=1)
    at ../../src/mesa/main/uniforms.c:181
#3  0x00007ffff7d41ad1 in stub_glUniform1i (location=0, v0=1)
    at /GFX/Test/Piglit/piglit/tests/util/piglit-dispatch-gen.c:52781
#4  0x0000000000400dd2 in piglit_init (argc=1, argv=0x7fffffffe1e8)
    at /GFX/Test/Piglit/piglit/tests/spec/arb_explicit_uniform_location/use-of-unused-loc.c:69
#5  0x00007ffff7d851dc in run_test (gl_fw=0x603010, argc=1,
    argv=0x7fffffffe1e8)
    at /GFX/Test/Piglit/piglit/tests/util/piglit-framework-gl/piglit_winsys_framework.c:72
#6  0x00007ffff7d6a885 in piglit_gl_test_run (argc=1, argv=0x7fffffffe1e8,
    config=0x7fffffffe0b0)
    at /GFX/Test/Piglit/piglit/tests/util/piglit-framework-gl.c:151
#7  0x0000000000400d58 in main (argc=1, argv=0x7fffffffe1e8)
    at /GFX/Test/Piglit/piglit/tests/spec/arb_explicit_uniform_location/use-of-unused-loc.c:36

Reproduce steps:
-------------------------
1. xinit
2. bin/arb_explicit_uniform_location-use-of-unused-loc -auto