SPV: Debug output: Include OpLine information for execution path.

Note that declaratives are not handled, only procedurals.

Test/spv.debugInfo.frag

@@ -8,15 +8,45 @@ uniform ubuf {
     S s;
 };
 
+uniform sampler2D s2d;
+
 layout(location = 0) in vec4 inv;
 layout(location = 0) out vec4 outv;
 
-void foo(S s)
+vec4 foo(S s)
 {
-    outv = s.a * inv;
+    vec4 r = s.a * inv;
+    ++r;
+    if (r.x > 3.0)
+        --r;
+    else
+        r *= 2;
+
+    return r;
 }
 
 void main()
 {
-    foo(s);
+    outv = foo(s);
+    outv += texture(s2d, vec2(0.5));
+
+    switch (s.a) {
+    case 10:
+        ++outv;
+        break;
+    case 20:
+        outv = 2 * outv;
+        ++outv;
+        break;
+    default:
+        --outv;
+        break;
+    }
+
+    for (int i = 0; i < 10; ++i)
+        outv *= 3.0;
+
+    outv.x < 10.0 ?
+        outv = sin(outv) :
+        outv = cos(outv);
 }