C++: test changes from previous commit

The IR for the conversion to bool results in a comparison where the left
hand side is not the result of any expression in the AST, so they can't
be usefully converted back to the AST

Author: Robert Marsh

cpp/ql/test/library-tests/controlflow/guards-ir/ASTGuardsCompare.expected

@@ -14,8 +14,6 @@
 | 17 | y < 1+1 when ... > ... is false |
 | 17 | y >= 1+1 when ... && ... is true |
 | 17 | y >= 1+1 when ... > ... is true |
-| 18 | call to get != call to get+0 when call to get is true |
-| 18 | call to get == call to get+0 when call to get is false |
 | 26 | 0 < x+0 when ... > ... is true |
 | 26 | 0 >= x+0 when ... > ... is false |
 | 26 | x < 0+1 when ... > ... is false |

cpp/ql/test/library-tests/controlflow/guards-ir/ASTGuardsEnsure.expected

@@ -154,7 +154,6 @@
 | test.c:109:9:109:23 | ... \|\| ... | test.c:109:23:109:23 | 0 | < | test.c:109:19:109:19 | y | 1 | 113 | 113 |
 | test.c:109:19:109:23 | ... < ... | test.c:109:19:109:19 | y | >= | test.c:109:23:109:23 | 0 | 0 | 113 | 113 |
 | test.c:109:19:109:23 | ... < ... | test.c:109:23:109:23 | 0 | < | test.c:109:19:109:19 | y | 1 | 113 | 113 |
-| test.cpp:18:8:18:10 | call to get | test.cpp:18:8:18:10 | call to get | != | test.cpp:18:8:18:10 | call to get | 0 | 19 | 19 |
 | test.cpp:31:7:31:13 | ... == ... | test.cpp:31:7:31:7 | x | != | test.cpp:31:12:31:13 | - ... | 0 | 30 | 30 |
 | test.cpp:31:7:31:13 | ... == ... | test.cpp:31:7:31:7 | x | != | test.cpp:31:12:31:13 | - ... | 0 | 34 | 34 |
 | test.cpp:31:7:31:13 | ... == ... | test.cpp:31:7:31:7 | x | == | test.cpp:31:12:31:13 | - ... | 0 | 30 | 30 |