Fix 8-bit storage nearly always using the

UniformAndStorageBuffer8BitAccess capability.

When using the 8-bit storage extension it basically always used the
`UniformAndStorageBuffer8BitAccess` capability, even in cases where it
wasn't required. For instance if we are targeting Vulkan 1.1 (SPIR-V 1.3
or higher), and we are only using 8-bit types in an SSBO, we only need
the `StorageBuffer8BitAccess` capability.

I fixed this by enabling storage buffer use in Vulkan 1.1 / SPIR-V 1.3
or higher, and then changing the logic to match.

I also added some tests that will output different capabilities when run
on Vulkan 1.0 and 1.1, thus they are added twice to the test list (one
for each version).

Fixes #1539

Test/baseResults/spv.1.3.8bitstorage-ssbo.vert.out

@@ -0,0 +1,56 @@
+spv.1.3.8bitstorage-ssbo.vert
+// Module Version 10300
+// Generated by (magic number): 80007
+// Id's are bound by 28
+
+                              Capability Shader
+                              Capability CapabilityStorageBuffer8BitAccess
+                              Extension  "SPV_KHR_8bit_storage"
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Vertex 4  "main" 9 18
+                              Source GLSL 450
+                              SourceExtension  "GL_EXT_shader_8bit_storage"
+                              Name 4  "main"
+                              Name 9  "color"
+                              Name 12  "Vertices"
+                              MemberName 12(Vertices) 0  "vertices"
+                              Name 14  ""
+                              Name 18  "gl_VertexIndex"
+                              Decorate 9(color) Location 0
+                              Decorate 11 ArrayStride 1
+                              MemberDecorate 12(Vertices) 0 NonWritable
+                              MemberDecorate 12(Vertices) 0 Offset 0
+                              Decorate 12(Vertices) Block
+                              Decorate 14 DescriptorSet 0
+                              Decorate 14 Binding 0
+                              Decorate 18(gl_VertexIndex) BuiltIn VertexIndex
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+               7:             TypeVector 6(float) 4
+               8:             TypePointer Output 7(fvec4)
+        9(color):      8(ptr) Variable Output
+              10:             TypeInt 8 0
+              11:             TypeRuntimeArray 10(int8_t)
+    12(Vertices):             TypeStruct 11
+              13:             TypePointer StorageBuffer 12(Vertices)
+              14:     13(ptr) Variable StorageBuffer
+              15:             TypeInt 32 1
+              16:     15(int) Constant 0
+              17:             TypePointer Input 15(int)
+18(gl_VertexIndex):     17(ptr) Variable Input
+              20:             TypePointer StorageBuffer 10(int8_t)
+              23:             TypeInt 32 0
+         4(main):           2 Function None 3
+               5:             Label
+              19:     15(int) Load 18(gl_VertexIndex)
+              21:     20(ptr) AccessChain 14 16 19
+              22:  10(int8_t) Load 21
+              24:     23(int) UConvert 22
+              25:     15(int) Bitcast 24
+              26:    6(float) ConvertSToF 25
+              27:    7(fvec4) CompositeConstruct 26 26 26 26
+                              Store 9(color) 27
+                              Return
+                              FunctionEnd