Modified tests to pass without using grep

Now directly test individual lines with perls regex matching rather than
calling out to grep. Some changes were required:

- escape (,  ) if we want to match them
- unescape (, ) if we want to use them as regex bracket groups
- escape +, $ if we want to use them as actual characters
- unescape + to use as a regex +

Author: thk123

regression/ansi-c/struct6/test.desc

@@ -1,7 +1,7 @@
 CORE
 main.c
 
-^EXIT=\(64\|1\)$
+^EXIT=(64|1)$
 ^SIGNAL=0$
 ^main.c:2:1: error: incomplete type not permitted here$
 ^CONVERSION ERROR$

regression/ansi-c/struct7/test.desc

@@ -1,7 +1,7 @@
 CORE
 main.c
 
-^EXIT=\(64\|1\)$
+^EXIT=(64|1)$
 ^SIGNAL=0$
 ^main.c:4:1: error: duplicate member .*$
 ^CONVERSION ERROR$

regression/cbmc-concurrency/constant_prop1/test.desc

@@ -4,6 +4,6 @@ main.c
 ^EXIT=0$
 ^SIGNAL=0$
 ^VERIFICATION SUCCESSFUL$
-^Generated 1 VCC(s), 0 remaining after simplification$
+^Generated 1 VCC\(s\), 0 remaining after simplification$
 --
 ^warning: ignoring

regression/cbmc-concurrency/pthread_join1/test.desc

@@ -5,6 +5,6 @@ main.c
 ^SIGNAL=0$
 ^\[main\.assertion\.1\] assertion i==1: FAILURE$
 ^\[main\.assertion\.2\] assertion i==2: SUCCESS$
-^\*\* 1 of 2 failed (2 iterations)$
+^\*\* 1 of 2 failed \(2 iterations\)$
 --
 ^warning: ignoring

regression/cbmc-cover/branch3/test.desc

@@ -3,6 +3,6 @@ main.c
 --cover branch --unwind 6
 ^EXIT=0$
 ^SIGNAL=0$
-^\*\* 23 of 23 covered (100.0%)$
+^\*\* 23 of 23 covered \(100.0%\)$
 --
 ^warning: ignoring

regression/cbmc-cover/branch4/test.desc

@@ -3,6 +3,6 @@ main.c
 --cover branch
 ^EXIT=0$
 ^SIGNAL=0$
-^\*\* 1 of 1 covered (100.0%)$
+^\*\* 1 of 1 covered \(100.0%\)$
 --
 ^warning: ignoring

regression/cbmc-cover/condition1/test.desc

@@ -13,6 +13,6 @@ main.c
 ^\[main.coverage.8] file main.c line 14 function main condition .* true: SATISFIED
 ^\[main.coverage.9] file main.c line 16 function main condition .* false: FAILED
 ^\[main.coverage.10] file main.c line 16 function main condition .* true: SATISFIED
-^\*\* 9 of 10 covered (90.0%)
+^\*\* 9 of 10 covered \(90.0%\)
 --
 ^warning: ignoring

regression/cbmc-cover/cover1/test.desc

@@ -6,6 +6,6 @@ main.c
 ^\[main.coverage.1] file main.c line 8 function main condition .*: SATISFIED$
 ^\[main.coverage.2] file main.c line 9 function main condition .*: SATISFIED$
 ^\[main.coverage.3] file main.c line 13 function main condition .*: FAILED$
-^\*\* 2 of 3 covered (66.7%)$
+^\*\* 2 of 3 covered \(66.7%\)$
 --
 ^warning: ignoring

regression/cbmc-cover/decision1/test.desc

@@ -3,6 +3,6 @@ main.c
 --cover decision
 ^EXIT=0$
 ^SIGNAL=0$
-^\*\* 2 of 2 covered (100.0%)$
+^\*\* 2 of 2 covered \(100.0%\)$
 --
 ^warning: ignoring

regression/cbmc-cover/location1/test.desc

@@ -8,6 +8,6 @@ main.c
 ^\[main.coverage.3\] file main.c line 13 function main block 3: SATISFIED$
 ^\[main.coverage.4\] file main.c line 15 function main block 4: FAILED$
 ^\[main.coverage.5\] file main.c line 17 function main block 5: SATISFIED$
-^\*\* 4 of 5 covered (80.0%)
+^\*\* 4 of 5 covered \(80.0%\)
 --
 ^warning: ignoring