test(buffer): add tests for improving coverage

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
test(exception): add tests for improving coverage

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(kernel): the hash code of expressions was not being used to compare them

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(name_generator): add name_generator for unique names modulo a prefix

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(debug): add assert_ne (not equal) macro

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(list): improve append function

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(splay_tree): add fold and for_each templates for splay_tree and splay_map

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(splay_map): add 'const' to coersion operator of ref class

[skip ci]
test(library): add tests for improving coverage

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
test(mpz): add unit tests for mpz

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
chore(testcov): add compile target "cov" to run code-coverage locally

 - need to run cmake with "-DTESTCOV=ON" and "-DCMAKE_BUILD_TYPE=Debug"
 - type "make/ninja cov"
 - open "coverage/index.html" to check the code coverage
feat(splay_map): add operator<< to splay_map for debugging
check point
style