scan-build: Add support of the option --exclude like in scan-build-py
Summary:
To exclude thirdparty code.
To test:
With /tmp/foo.c
```
void test() {
int x;
x = 1; // warn
}
```
```
$ scan-build --exclude non-existing/ --exclude /tmp/ -v gcc -c foo.c
scan-build: Using '/usr/lib/llvm-7/bin/clang' for static analysis
scan-build: Emitting reports for this run to '/tmp/scan-build-2018-09-16-214531-8410-1'.
foo.c:3:3: warning: Value stored to 'x' is never read
x = 1; // warn
^ ~
1 warning generated.
scan-build: File '/tmp/foo.c' deleted: part of an ignored directory.
scan-build: 0 bugs found.
```
Reviewers: jroelofs
Reviewed By: jroelofs
Subscribers: whisperity, cfe-commits
Differential Revision: https://reviews.llvm.org/D52153
llvm-svn: 342359