POSIX: MSVC defines all of these

It also defines fpclassify(), but that's a more complex change
due to the classification macros in perl.h

ext/POSIX/t/math.t

@@ -83,9 +83,6 @@ SKIP: {
     if ($^O =~ /VMS/) {
         skip "running in $^O, C99 math support uneven";
     }
-    if ($Config{cc} =~ /\b(?:cl|icl)/) {
-        skip "Microsoft compiler - C99 math support uneven";
-    }
 
     near(M_SQRT2, 1.4142135623731, "M_SQRT2", 1e-9);
     near(M_E, 2.71828182845905, "M_E", 1e-9);

win32/config.vc

@@ -93,14 +93,14 @@ d__fwalk='undef'
 d_accept4='undef'
 d_access='define'
 d_accessx='undef'
-d_acosh='undef'
+d_acosh='define'
 d_aintl='undef'
 d_alarm='define'
 d_archlib='define'
 d_asctime64='undef'
 d_asctime_r='undef'
-d_asinh='undef'
-d_atanh='undef'
+d_asinh='define'
+d_atanh='define'
 d_atolf='undef'
 d_atoll='undef'
 d_attribute_always_inline='undef'
@@ -186,7 +186,7 @@ d_eofnblk='define'
 d_erf='undef'
 d_erfc='undef'
 d_eunice='undef'
-d_exp2='undef'
+d_exp2='define'
 d_expm1='undef'
 d_faststdio='define'
 d_fchdir='undef'
@@ -593,7 +593,7 @@ d_tcgetpgrp='undef'
 d_tcsetpgrp='undef'
 d_telldir='define'
 d_telldirproto='define'
-d_tgamma='undef'
+d_tgamma='define'
 d_thread_local='undef'
 d_thread_safe_nl_langinfo_l='undef'
 d_time='define'