C++: add literal tests

Author: Robert Marsh

cpp/ql/test/library-tests/valuenumbering/HashCons/GlobalValueNumbering.expected

@@ -33,3 +33,19 @@
 | test.cpp:79:11:79:14 | vals | 79:c11-c14 79:c24-c27 |
 | test.cpp:92:11:92:11 | x | 92:c11-c11 93:c10-c10 |
 | test.cpp:97:3:97:3 | x | 97:c3-c3 98:c3-c3 |
+| test.cpp:103:10:103:11 | 1 | 103:c10-c11 104:c7-c7 107:c7-c7 108:c7-c7 10:c16-c16 |
+| test.cpp:104:3:104:3 | x | 104:c3-c3 105:c3-c3 106:c3-c3 107:c3-c3 108:c3-c3 |
+| test.cpp:105:7:105:7 | 2 | 105:c7-c7 106:c7-c7 107:c11-c11 108:c11-c11 21:c16-c16 |
+| test.cpp:107:7:107:11 | ... + ... | 107:c7-c11 108:c7-c11 35:c16-c16 |
+| test.cpp:110:15:110:17 | 1 | 110:c15-c17 111:c9-c11 |
+| test.cpp:110:15:110:17 | (char *)... | 110:c15-c17 111:c9-c11 |
+| test.cpp:110:15:110:17 | array to pointer conversion | 110:c15-c17 111:c9-c11 |
+| test.cpp:111:3:111:5 | str | 111:c3-c5 112:c3-c5 113:c3-c5 |
+| test.cpp:112:9:112:11 | 2 | 112:c9-c11 113:c9-c11 |
+| test.cpp:112:9:112:11 | (char *)... | 112:c9-c11 113:c9-c11 |
+| test.cpp:112:9:112:11 | array to pointer conversion | 112:c9-c11 113:c9-c11 |
+| test.cpp:115:13:115:15 | 0.0 | 115:c13-c15 116:c7-c9 |
+| test.cpp:115:13:115:15 | (float)... | 115:c13-c15 116:c7-c9 |
+| test.cpp:116:3:116:3 | y | 116:c3-c3 117:c3-c3 118:c3-c3 |
+| test.cpp:117:7:117:9 | 0.10000000000000001 | 117:c7-c9 118:c7-c9 |
+| test.cpp:117:7:117:9 | (float)... | 117:c7-c9 118:c7-c9 |

cpp/ql/test/library-tests/valuenumbering/HashCons/test.cpp

@@ -98,3 +98,22 @@ void test06(int x) {
   x++; // x is matched but x++ is not matched?
 }
 
+// literals
+void test07() {
+  int x = 1;
+  x = 1;
+  x = 2;
+  x = 2;
+  x = 1 + 2;
+  x = 1 + 2;
+
+  char *str = "1";
+  str = "1";
+  str = "2";
+  str = "2";
+
+  float y = 0.0;
+  y = 0.0;
+  y = 0.1;
+  y = 0.1;
+}