Create unit test for comparison against a negated constant vector.

Change-Id: Ibc1a8d3ebbf62cc55d013f7d9146f6b155d11da2
Bug: oss-fuzz:26830, oss-fuzz:26789
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/332377
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

Author: johnstiles-google

tests/sksl/shared/NegatedVectorLiteral.sksl

@@ -1,6 +1,5 @@
 void main() {
-    if (half4(1) == half4(-half2(-1), half2(1)))
-        sk_FragColor = half4(1);
-    else
-        sk_FragColor = half4(-1);
+    sk_FragColor.r = (half4(1) == half4(-half2(-1), half2(1))) ? 1 : 0;
+    sk_FragColor.g = (half4(1) == -half4(1)) ? 1 : 0;
+    sk_FragColor.b = (half4(0) == -half4(0)) ? 1 : 0;
 }

tests/sksl/shared/golden/NegatedVectorLiteral.glsl

@@ -1,5 +1,3 @@
+### Compilation failed:
+
 
-out vec4 sk_FragColor;
-void main() {
-    sk_FragColor = vec4(1.0);
-}

tests/sksl/shared/golden/NegatedVectorLiteral.metal

@@ -1,14 +1,3 @@
-#include <metal_stdlib>
-#include <simd/simd.h>
-using namespace metal;
-struct Inputs {
-};
-struct Outputs {
-    float4 sk_FragColor [[color(0)]];
-};
-fragment Outputs fragmentMain(Inputs _in [[stage_in]], bool _frontFacing [[front_facing]], float4 _fragCoord [[position]]) {
-    Outputs _outputStruct;
-    thread Outputs* _out = &_outputStruct;
-    _out->sk_FragColor = float4(1.0);
-    return *_out;
-}
+### Compilation failed:
+
+