tidy-up: miscellaneous

- vms/curlmsg_vms.h: delete unused/commented code.
- vtls/schannel_verify: sort includes.
- typecheck-gcc.h: fix indent and alignment.
- lib/config-win32.h: drop idle `#undef`.
- spacecheck: check for stray empty lines before after curly braces.
- make literals more readable: 1048576 -> 1024 * 1024
- scope variables.
- use ISO date in a comment.
- drop redundant parentheses.
- drop empty comments.
- unfold lines.
- duplicate/stray spaces in comments.
- fix indent, whitespace, minor typos.

Closes #20690

lib/mprintf.c

@@ -32,10 +32,10 @@
 #define MAX_PARAMETERS 128 /* number of input arguments */
 #define MAX_SEGMENTS   128 /* number of output segments */
 
-/* Lower-case digits.  */
+/* Lower-case digits. */
 const unsigned char Curl_ldigits[] = "0123456789abcdef";
 
-/* Upper-case digits.  */
+/* Upper-case digits. */
 const unsigned char Curl_udigits[] = "0123456789ABCDEF";
 
 #define OUTCHAR(x)                                       \
@@ -131,9 +131,9 @@ struct asprintf {
 };
 
 /* the provided input number is 1-based but this returns the number 0-based.
-
-   returns -1 if no valid number was provided.
-*/
+ *
+ * returns -1 if no valid number was provided.
+ */
 static int dollarstring(const char *p, const char **end)
 {
   curl_off_t num;
@@ -596,8 +596,8 @@ static int parsefmt(const char *format,
 }
 
 struct mproperty {
-  int width;            /* Width of a field.  */
-  int prec;             /* Precision of a field.  */
+  int width;            /* Width of a field. */
+  int prec;             /* Precision of a field. */
   unsigned int flags;
 };
 
@@ -722,7 +722,7 @@ static bool out_number(void *userp,
   char *w;
 
   if(flags & FLAGS_CHAR) {
-    /* Character.  */
+    /* Character. */
     if(!(flags & FLAGS_LEFT))
       while(--width > 0)
         OUTCHAR(' ');
@@ -746,11 +746,11 @@ static bool out_number(void *userp,
     ;
 
   else {
-    /* Decimal integer.  */
+    /* Decimal integer. */
     is_neg = (nums < 0);
     if(is_neg) {
       /* signed_num might fail to hold absolute negative minimum by 1 */
-      int64_t signed_num; /* Used to convert negative in positive.  */
+      int64_t signed_num; /* Used to convert negative in positive. */
       signed_num = nums + (int64_t)1;
       signed_num = -signed_num;
       num = (uint64_t)signed_num;
@@ -758,11 +758,11 @@ static bool out_number(void *userp,
     }
   }
 
-  /* Supply a default precision if none was given.  */
+  /* Supply a default precision if none was given. */
   if(prec == -1)
     prec = 1;
 
-  /* Put the number in WORK.  */
+  /* Put the number in WORK. */
   w = workend;
   DEBUGASSERT(base <= 16);
   switch(base) {
@@ -822,7 +822,7 @@ static bool out_number(void *userp,
     while(width-- > 0)
       OUTCHAR('0');
 
-  /* Write the number.  */
+  /* Write the number. */
   while(++w <= workend) {
     OUTCHAR(*w);
   }
@@ -848,7 +848,7 @@ static bool out_string(void *userp,
   size_t len;
 
   if(!str) {
-    /* Write null string if there is space.  */
+    /* Write null string if there is space. */
     if(prec == -1 || prec >= (int)sizeof(nilstr) - 1) {
       str = nilstr;
       len = sizeof(nilstr) - 1;
@@ -895,17 +895,17 @@ static bool out_pointer(void *userp,
                         char *work,
                         int *donep)
 {
-  /* Generic pointer.  */
+  /* Generic pointer. */
   if(ptr) {
     size_t num = (size_t)ptr;
 
-    /* If the pointer is not NULL, write it as a %#x spec.  */
+    /* If the pointer is not NULL, write it as a %#x spec. */
     p->flags |= FLAGS_HEX | FLAGS_ALT;
     if(out_number(userp, stream, p, num, 0, work, donep))
       return TRUE;
   }
   else {
-    /* Write "(nil)" for a nil pointer.  */
+    /* Write "(nil)" for a nil pointer. */
     const char *point;
     int width = p->width;
     int flags = p->flags;
@@ -946,7 +946,7 @@ static int formatf(void *userp, /* untouched by format(), just sent to the
                    const char *format, /* %-formatted string */
                    va_list ap_save) /* list of parameters */
 {
-  int done = 0;   /* number of characters written  */
+  int done = 0;   /* number of characters written */
   int i;
   int ocount = 0; /* number of output segments */
   int icount = 0; /* number of input arguments */
@@ -1042,7 +1042,7 @@ static int formatf(void *userp, /* untouched by format(), just sent to the
       break;
 
     case MTYPE_INTPTR:
-      /* Answer the count of characters written.  */
+      /* Answer the count of characters written. */
       if(p.flags & FLAGS_LONGLONG)
         *(int64_t *)iptr->val.ptr = (int64_t)done;
       else