Add support for GL_EXT_buffer_reference2

Test/spv.bufferhandle18.frag

@@ -0,0 +1,59 @@
+#version 450
+
+#extension GL_EXT_shader_explicit_arithmetic_types_int64 : enable
+#extension GL_EXT_buffer_reference2 : enable
+#extension GL_EXT_scalar_block_layout : enable
+
+layout(buffer_reference, buffer_reference_align = 8) buffer T1 {
+    int x;
+    bool y;
+};
+layout(buffer_reference, buffer_reference_align = 64) buffer T2 {
+    int x;
+};
+
+const int s = int(uint64_t(T1(T2(uint64_t(3)))));
+int x[s];
+const uint64_t t = uint64_t(true ? T2(uint64_t(10)) : T2(uint64_t(11)));
+
+
+#define sizeof(T) (uint64_t(T(uint64_t(0))+1))
+
+const uint64_t s2 = sizeof(T1);
+uint buf[int(s2)];
+
+
+void main()
+{
+    T1 a = T1(uint64_t(4)), b = T1(uint64_t(5));
+    T1 c = true ? a : b;
+    T1 d = (a,b);
+    T1 e = true ? T1(uint64_t(6)) : T1(uint64_t(7));
+    T1 f = a.y ? T1(uint64_t(8)) : T1(uint64_t(9));
+
+    f[3].x = 1;
+    (f+5).x = 1;
+
+    T1 arr[2] = {a, f};
+    arr[1][7].x = 1;
+    int i;
+    arr[i][i].x = 1;
+    // Since we don't distinguish between "pointer" and "reference" type,
+    // a reference type can have [] applied to it repeatedly and it has
+    // the effect of adding up the indices.
+    arr[i][i][i][i][i][i][i].x = 1;
+
+    T1 j;
+    j = j+1;
+    j = j-2;
+    j += 3;
+    j -= 4;
+    j = 5+j;
+    T1 k = j + 6;
+    int64_t x = k - j;
+    uint64_t y = sizeof(T1);
+    k = k + (-1);
+
+    T2 m;
+    m = m+1;
+}