About c++ CWE-022 example files, CWE-022 ql file does not seem to detect vulnerabilities.

**Description of the issue**

### << codeql version >>
CodeQL command-line toolchain release 2.14.6.

### << codeql command test context >>
(a-1) Cloning codeql 'main' branch
`git clone https://github.com/github/codeql.git codeql-main-clone`

(a-2) Use reference c file in the CWE-022 directory
`/home/junseok/workdir/codeql` is my directory path.

/home/junseok/workdir/codeql/**codeql-main-clone/cpp/ql/src/Security/CWE/CWE-022**

CWE-022 directory contains...
TaintedPath.c
TaintedPath.qhelp
TaintedPath.ql

(a-3) Add makefile to the CWE-022 directory for database creation

<< makefile >>
```
CC = gcc
CFLAGS = -Wall

SRCS=$(wildcard *.c)

OBJS=$(SRCS:.c=.o)

all: $(OBJS)

${OBJS} : %.o: %.c Makefile
-$(CC) $(CFLAGS) -c $<
```

(b-1) database creation
```
codeql database create \
--language=cpp \
--command=make \
--source-root=/home/junseok/workdir/codeql/codeql-main-clone/cpp/ql/src/Security/CWE/CWE-022 \
--overwrite \
/home/junseok/workdir/codeql-database \
--verbosity=errors 2>&1 > build.log

```

(b-2) Print build.log (database creation log file)
```
[2023-10-03 16:08:58] [build-stdout] gcc -Wall -c TaintedPath.c
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c: In function ‘main’:
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:5:21: error: ‘FILENAME_MAX’ undeclared (first use in this function)
[2023-10-03 16:08:58] [build-stderr] char fileBuffer[FILENAME_MAX] = "/home/";
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:5:21: note: each undeclared identifier is reported only once for each function it appears in
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:7:5: error: unknown type name ‘size_t’
[2023-10-03 16:08:58] [build-stderr] size_t len = strlen(fileName);
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:7:5: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration]
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:7:18: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default]
[2023-10-03 16:08:58] [build-stderr] size_t len = strlen(fileName);
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:8:5: warning: implicit declaration of function ‘strncat’ [-Wimplicit-function-declaration]
[2023-10-03 16:08:58] [build-stderr] strncat(fileName+len, userAndFile, FILENAME_MAX-len-1);
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:8:5: warning: incompatible implicit declaration of built-in function ‘strncat’ [enabled by default]
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:10:5: warning: implicit declaration of function ‘fopen’ [-Wimplicit-function-declaration]
[2023-10-03 16:08:58] [build-stderr] fopen(fileName, "wb+");
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:5:10: warning: unused variable ‘fileBuffer’ [-Wunused-variable]
[2023-10-03 16:08:58] [build-stderr] char fileBuffer[FILENAME_MAX] = "/home/";
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:16:5: error: unknown type name ‘size_t’
[2023-10-03 16:08:58] [build-stderr] size_t len = strlen(fileName);
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:16:18: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default]
[2023-10-03 16:08:58] [build-stderr] size_t len = strlen(fileName);
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:19:5: warning: incompatible implicit declaration of built-in function ‘strncat’ [enabled by default]
[2023-10-03 16:08:58] [build-stderr] strncat(fileName+len, fixed, FILENAME_MAX-len-1);
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:14:10: warning: unused variable ‘fileBuffer’ [-Wunused-variable]
[2023-10-03 16:08:58] [build-stderr] char fileBuffer[FILENAME_MAX] = "/home/";
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] TaintedPath.c:22:1: warning: control reaches end of non-void function [-Wreturn-type]
[2023-10-03 16:08:58] [build-stderr] }
[2023-10-03 16:08:58] [build-stderr] ^
[2023-10-03 16:08:58] [build-stderr] make: [TaintedPath.o] Error 1 (ignored)
```

(c) database analysis
```
codeql database analyze \
/home/junseok/workdir/codeql-database \
--format=csv \
--threads 4 \
--output=/home/junseok/workdir/cpp-ql-cwe-22-output \
/home/junseok/workdir/codeql/codeql-main-clone/cpp/ql/src/Security/CWE/CWE-022/TaintedPath.ql \
--verbosity=errors

```

(d) output of database analysis

`cat cpp-ql-cwe-22-output` command shows empty results.

### << Questions >>
Why can't the ql file for CWE-022 detect vulnerabilities in c file for CWE-022?
Is it not detected due to errors that exist during the build process?