Hardware: BSW RVP

Bug detailed description
=======
The following drawElements tests appear to have regressed between Mesa 10.5.0 and 10.6.0:
- dEQP-GLES3.functional.rasterization.fbo.rbo_multisample_4.interpolation.lines_wide
- dEQP-GLES3.functional.rasterization.fbo.rbo_multisample_max.interpolation.lines_wide

Cases where the test passed:
- ChromeOS on BSW w/ mid-November commit of Mesa (on platforms Haswell, Baytrail, Broadwell and Braswell - not sure of the commit on this)
- ChromeOS w/ mesa commit we were trying to move to (c2a0600 i965: Don't set NirOptions for stages that will use the vec4 backend.) on platforms Haswell, Baytrail, Broadwell - possible BSW-only regression

Cases where the test failed:
- ChromeOS build (bsw system) from current Google upstream tree (same mid-November Mesa commit)
- Upstream Linux (bsw system) using Mesa commit from 2014-11-24; commit ID: c88385603ae8d983314b736a9459bbf7d002cf11
- ChromeOS build (bsw system) w/ mesa commit we were trying to move to (c2a0600 i965: Don't set NirOptions for stages that will use the vec4 backend.)
- Upstream Linux (bsw system) using the mesa commit we were trying to move to
- Upstream Linux (bsw system) using current ToT mesa (as of 5/20/15)

Reproduce Steps
==============
1. Run indicated drawElements test with indicated version of Mesa or ToT Mesa
2. Compare test results against older (mid-November) Mesa commit

Expected Result
=============
- No failure with current ToT Mesa

Actual Result
===========
- "129 invalid pixel(s) found"

Full diff between "before" test result and "after" test result
**********
< <Text>ALIASED_LINE_WIDTH_RANGE = [1, 7.875]</Text>
—
> <Text>ALIASED_LINE_WIDTH_RANGE = [1, 40]</Text>
25c25,79
< <Text>Line width 10 not supported, skipping iteration.</Text>
—
> <Text>Generated vertices:</Text>
> <Text> (0.506412, 0.560052, 0, 1), color= (1, 0, 0, 1)</Text>
> <Text> (-0.592623, 0.70225, 0, 1), color= (0, 1, 0, 1)</Text>
> <Text> (-0.835676, 0.874938, 0, 1), color= (0, 0, 1, 1)</Text>
> <Text> (-0.143044, 0.0755453, 0, 1), color= (1, 0, 0, 1)</Text>
> <Text> (0.256429, -0.591691, 0, 1), color= (0, 1, 0, 1)</Text>
> <Text> (-0.0305212, -0.827533, 0, 1), color= (0, 0, 1, 1)</Text>
> <Text>Verifying rasterization result. Native format is RGB888</Text>
> <Text>Found an invalid pixel at (132,23)
> Pixel color: RGBA(0, 35, 188, 255)
> Native color: (0, 35, 188)
> Allowed error: (0, 0, 0)
> Reference native color min: (0, 35, 209)
> Reference native color max: (0, 45, 222)
> Reference native float min: (0, 35.262, 209.348)
> Reference native float max: (0, 44.3039, 221.181)
> Fmin: (0, 0.138282, 0.820972)
> Fmax: (0, 0.173741, 0.867377)
> </Text>
> <Text>Found an invalid pixel at (126,29)
> Pixel color: RGBA(0, 31, 192, 255)
> Native color: (0, 31, 192)
> Allowed error: (0, 0, 0)
> Reference native color min: (0, 30, 213)
> Reference native color max: (0, 40, 226)
> Reference native float min: (0, 30.952, 213.751)
> Reference native float max: (0, 39.8586, 225.585)
> Fmin: (0, 0.12138, 0.838239)
> Fmax: (0, 0.156308, 0.884647)
> </Text>
> <Text>Found an invalid pixel at (131,33)
> Pixel color: RGBA(0, 61, 162, 255)
> Native color: (0, 61, 162)
> Allowed error: (0, 0, 0)
> Reference native color min: (0, 64, 179)
> Reference native color max: (0, 75, 192)
> Reference native float min: (0, 64.7962, 179.538)
> Reference native float max: (0, 74.5473, 191.223)
> Fmin: (0, 0.254103, 0.704071)
> Fmax: (0, 0.292342, 0.749893)
> </Text>
> <Text>Found an invalid pixel at (132,34)
> Pixel color: RGBA(0, 67, 156, 255)
> Native color: (0, 67, 156)
> Allowed error: (0, 0, 0)
> Reference native color min: (0, 72, 172)
> Reference native color max: (0, 83, 184)
> Reference native float min: (0, 72.3003, 172.034)
> Reference native float max: (0, 82.1287, 183.641)
> Fmin: (0, 0.283531, 0.674643)
> Fmax: (0, 0.322073, 0.720162)
> </Text>
> <Text>Omitted 12 pixel error description(s).</Text>
> <Text>16 invalid pixel(s) found.</Text>
> <ImageSet Name="Verification result" Description="Result of rendering" />
36c90,103
< <Text>No invalid pixels found.</Text>
—
> <Text>Found an invalid pixel at (208,30)
> Pixel color: RGBA(0, 1, 31, 255)
> Expected background color.
> </Text>
> <Text>Found an invalid pixel at (209,30)
> Pixel color: RGBA(0, 3, 93, 255)
> Expected background color.
> </Text>
> <Text>Found an invalid pixel at (204,31)
> Pixel color: RGBA(0, 7, 89, 255)
> Expected background color.
> </Text>
> <Text>Omitted 125 pixel error description(s).</Text>
> <Text>129 invalid pixel(s) found.</Text>
39,40c106,107
< <Number Name="TestDuration" Description="Test case duration in microseconds" Tag="Time" Unit="us">183831</Number>
< <Result StatusCode="Pass">Pass</Result>
—
> <Number Name="TestDuration" Description="Test case duration in microseconds" Tag="Time" Unit="us">503174</Number>
> <Result StatusCode="Fail">Found invalid pixel values</Result>