On a GTX 650, the following 6 pow tests fail with the nouveau drivers but pass
with the nvidia proprietary driver:

https://www.khronos.org/registry/webgl/conformance-suites/1.0.2/conformance/ogles/GL/pow/pow_009_to_016.html

test: pow_float_frag_xconsthalf_yvary.test.html
FAIL pixel @ (33, 33 was [45,0,0,255] expected [16,0,0,255]

test: pow_vec2_frag_xconsthalf_yvary.test.html
FAIL pixel @ (33, 33 was [45,90,0,255] expected [16,255,0,255]

test: pow_vec3_vert_xconsthalf_yvary.test.html
FAIL pixel @ (33, 33 was [45,90,90,255] expected [16,255,255,255]

https://www.khronos.org/registry/webgl/conformance-suites/1.0.2/conformance/ogles/GL/pow/pow_017_to_024.html

test: pow_float_vert_xconsthalf_yvary.test.html
FAIL pixel @ (33, 33 was [45,0,0,255] expected [16,0,0,255]

test: pow_vec2_vert_xconsthalf_yvary.test.html
FAIL pixel @ (33, 33 was [45,90,0,255] expected [16,255,0,255]

test: pow_vec3_vert_xconsthalf_yvary.test.html
FAIL pixel @ (33, 33 was [45,90,90,255] expected [16,255,255,255]