Types: Fix #1290: Rationalize and correct "mixed" style array dimensioning.

There a couple functional problems, which when reduced down also led to
some good simplifications and rationalization.  So, this commit:
 - corrects "mixed" functionality: int[A] f[B] -> f[B][A]
 - correct multi-identifier decls: int[A] f[B], g[C] -> f and g are independently sized.
 - increases symmetry between different places in the code that do this
 - makes fewer ways to do the same thing; several methods are just gone now
 - makes more clear when something is copied or shared

Test/mixedArrayDecls.frag

@@ -0,0 +1,30 @@
+#version 450
+
+struct S {
+    int[3] a[2], b[5];
+};
+
+S s;
+
+int[5] c[4], d[8];
+int[9] e[], f[];
+int e[11][9];
+int f[13][9];
+
+int[14] g[], h[];
+
+int [14][15][6] foo(int[6] p[14][15]) { return p; }
+
+void main()
+{
+    g[3];
+    h[2];
+}
+
+float[4][3][2] bar() { float[3][2] a[4]; return a; }
+
+in inbname {
+    float[7] f[8][9];
+} inbinst[4][5][6];
+
+float[3][2] barm[4]() { float[3][2] a[4]; return a; }  // ERROR