420Pack: Implement length() on vectors and matrices. Also, tweak line-continuation semantics to understand the extension.

git-svn-id: https://cvs.khronos.org/svn/repos/ogl/trunk/ecosystem/public/sdk/tools/glslang@26601 e7fa87d3-cd2b-0410-9028-fcbf551c1848

Test/420.vert

@@ -83,4 +83,16 @@ out gl_PerVertex {
 };
 
 patch in vec4 patchIn;              // ERROR
-patch out vec4 patchOut;            // ERROR
+patch out vec4 patchOut;            // ERROR
+
+void bar23444()
+{
+    mat4x3 m43;  \
+    float a1 = m43[3].y;
+    vec3 v3;
+    int a2 = m43.length();
+    a2 += m43[1].length();
+    a2 += v3.length();
+    const float b = 2 * a1;
+    int a = gl_MinProgramTexelOffset + gl_MaxProgramTexelOffset;
+}