Always correctly terminate main. Issue #588, PR #600.

Test/baseResults/hlsl.array.implicit-size.frag.out

@@ -234,6 +234,7 @@ gl_FragCoord origin is upper left
                               Store 18(g_array) 24
                               Store 28(g_array_unused) 31
                               Store 37(g_mystruct) 42
+                              Return
                               FunctionEnd
 12(main(struct-PS_OUTPUT-vf41;):           2 Function None 10
    11(ps_output):      9(ptr) FunctionParameter

Test/baseResults/hlsl.float1.frag.out

@@ -92,6 +92,7 @@ gl_FragCoord origin is upper left
                5:             Label
                               Store 14(f1) 15
                               Store 16(scalar) 17
+                              Return
                               FunctionEnd
 11(ShaderFunction(vf1;f1;):    6(float) Function None 8
      9(inFloat1):      7(ptr) FunctionParameter

Test/baseResults/hlsl.float4.frag.out

@@ -82,6 +82,7 @@ gl_FragCoord origin is upper left
               20:             TypePointer Uniform 7(fvec4)
 4(PixelShaderFunction):           2 Function None 3
                5:             Label
+                              Return
                               FunctionEnd
 11(ShaderFunction(vf4;):    7(fvec4) Function None 9
        10(input):      8(ptr) FunctionParameter

Test/baseResults/hlsl.intrinsics.vert.out

@@ -3011,6 +3011,7 @@ Shader version: 450
             1059:          76 ConstantComposite 1058 1058 1058 1058
 4(VertexShaderFunction):           2 Function None 3
                5:             Label
+                              Return
                               FunctionEnd
 16(VertexShaderFunctionS(f1;f1;f1;u1;u1;):    6(float) Function None 10
         11(inF0):      7(ptr) FunctionParameter

Test/baseResults/hlsl.layout.frag.out

@@ -119,6 +119,7 @@ gl_FragCoord origin is upper left
               38:     17(int) SpecConstant 10
          4(main):           2 Function None 3
                5:             Label
+                              Return
                               FunctionEnd
 11(PixelShaderFunction(vf4;):    7(fvec4) Function None 9
        10(input):      8(ptr) FunctionParameter

Test/baseResults/hlsl.matType.frag.out

@@ -90,6 +90,7 @@ gl_FragCoord origin is upper left
               29:     28(ptr) Variable Uniform
 4(PixelShaderFunction):           2 Function None 3
                5:             Label
+                              Return
                               FunctionEnd
 11(ShaderFunction(vf1;f1;):    6(float) Function None 8
      9(inFloat1):      7(ptr) FunctionParameter

Test/baseResults/hlsl.shapeConv.frag.out

@@ -282,6 +282,7 @@ gl_FragCoord origin is upper left
               62:             TypeVector 41(bool) 4
          4(main):           2 Function None 3
                5:             Label
+                              Return
                               FunctionEnd
 13(PixelShaderFunction(vf4;f1;):    7(fvec4) Function None 10
        11(input):      8(ptr) FunctionParameter

Test/baseResults/hlsl.swizzle.frag.out

@@ -106,6 +106,7 @@ gl_FragCoord origin is upper left
 4(PixelShaderFunction):           2 Function None 3
                5:             Label
                               Store 14(AmbientColor) 18
+                              Return
                               FunctionEnd
 11(ShaderFunction(vf4;):    7(fvec4) Function None 9
        10(input):      8(ptr) FunctionParameter

Test/baseResults/hlsl.typedef.frag.out

@@ -106,6 +106,7 @@ gl_FragCoord origin is upper left
               20:      9(int) Constant 2
 4(PixelShaderFunction):           2 Function None 3
                5:             Label
+                              Return
                               FunctionEnd
 14(ShaderFunction(vf4;i1;):    7(fvec4) Function None 11
        12(input):      8(ptr) FunctionParameter