Before this patch, it missed this in `curl/curl.h`:
```c
# define __has_declspec_attribute(x) 0
```
After this patch:
```
test 1167...[Verify curl prefix of public symbols in header files]
/usr/bin/perl -I. -I. returned 1, when expecting 0
1167: exit FAILED
== Contents of files in the log/14/ dir after test 1167
=== Start of file server.cmd
Testnum 1167
=== End of file server.cmd
=== Start of file stdout1167
Bad symbols in public header files:
__has_declspec_attribute(x)
=== End of file stdout1167
FAIL 1167: 'Verify curl prefix of public symbols in header files' source analysis
TESTFAIL: These test cases failed: 1167
```
Ref: #16491
Closes #16496
open H, "<$f";
while(<H>) {
my ($line, $linenum) = ($_, $.);
- if (/^#define +([^ \n]*)/) {
+ if (/^ *# *define +([^ \n]*)/) {
if($verbose) {
print "Source: $f\n";
print "Symbol: $1\n";