patch 8.1.2387: using old C style comments

Problem:    Using old C style comments.
Solution:   Use // comments where appropriate.

src/hashtab.c

@@ -30,18 +30,18 @@
 #include "vim.h"
 
 #if 0
-# define HT_DEBUG	/* extra checks for table consistency  and statistics */
+# define HT_DEBUG	// extra checks for table consistency  and statistics
 
-static long hash_count_lookup = 0;	/* count number of hashtab lookups */
-static long hash_count_perturb = 0;	/* count number of "misses" */
+static long hash_count_lookup = 0;	// count number of hashtab lookups
+static long hash_count_perturb = 0;	// count number of "misses"
 #endif
 
-/* Magic value for algorithm that walks through the array. */
+// Magic value for algorithm that walks through the array.
 #define PERTURB_SHIFT 5
 
 static int hash_may_resize(hashtab_T *ht, int minitems);
 
-#if 0 /* currently not used */
+#if 0 // currently not used
 /*
  * Create an empty hash table.
  * Returns NULL when out of memory.
@@ -64,7 +64,7 @@ hash_create(void)
     void
 hash_init(hashtab_T *ht)
 {
-    /* This zeroes all "ht_" entries and all the "hi_key" in "ht_smallarray". */
+    // This zeroes all "ht_" entries and all the "hi_key" in "ht_smallarray".
     vim_memset(ht, 0, sizeof(hashtab_T));
     ht->ht_array = ht->ht_smallarray;
     ht->ht_mask = HT_INIT_SIZE - 1;
@@ -165,7 +165,7 @@ hash_lookup(hashtab_T *ht, char_u *key, hash_T hash)
     for (perturb = hash; ; perturb >>= PERTURB_SHIFT)
     {
 #ifdef HT_DEBUG
-	++hash_count_perturb;	    /* count a "miss" for hashtab lookup */
+	++hash_count_perturb;	    // count a "miss" for hashtab lookup
 #endif
 	idx = (unsigned)((idx << 2U) + idx + perturb + 1U);
 	hi = &ht->ht_array[idx & ht->ht_mask];
@@ -231,7 +231,7 @@ hash_add_item(
     char_u	*key,
     hash_T	hash)
 {
-    /* If resizing failed before and it fails again we can't add an item. */
+    // If resizing failed before and it fails again we can't add an item.
     if (ht->ht_error && hash_may_resize(ht, 0) == FAIL)
 	return FAIL;
 
@@ -241,11 +241,11 @@ hash_add_item(
     hi->hi_key = key;
     hi->hi_hash = hash;
 
-    /* When the space gets low may resize the array. */
+    // When the space gets low may resize the array.
     return hash_may_resize(ht, 0);
 }
 
-#if 0  /* not used */
+#if 0  // not used
 /*
  * Overwrite hashtable item "hi" with "key".  "hi" must point to the item that
  * is to be overwritten.  Thus the number of items in the hashtable doesn't
@@ -318,7 +318,7 @@ hash_unlock(hashtab_T *ht)
     static int
 hash_may_resize(
     hashtab_T	*ht,
-    int		minitems)		/* minimal number of items */
+    int		minitems)		// minimal number of items
 {
     hashitem_T	temparray[HT_INIT_SIZE];
     hashitem_T	*oldarray, *newarray;
@@ -330,7 +330,7 @@ hash_may_resize(
     long_u	newmask;
     hash_T	perturb;
 
-    /* Don't resize a locked table. */
+    // Don't resize a locked table.
     if (ht->ht_locked > 0)
 	return OK;
 
@@ -343,8 +343,8 @@ hash_may_resize(
 
     if (minitems == 0)
     {
-	/* Return quickly for small tables with at least two NULL items.  NULL
-	 * items are required for the lookup to decide a key isn't there. */
+	// Return quickly for small tables with at least two NULL items.  NULL
+	// items are required for the lookup to decide a key isn't there.
 	if (ht->ht_filled < HT_INIT_SIZE - 1
 					 && ht->ht_array == ht->ht_smallarray)
 	    return OK;
@@ -360,9 +360,9 @@ hash_may_resize(
 	    return OK;
 
 	if (ht->ht_used > 1000)
-	    minsize = ht->ht_used * 2;  /* it's big, don't make too much room */
+	    minsize = ht->ht_used * 2;  // it's big, don't make too much room
 	else
-	    minsize = ht->ht_used * 4;  /* make plenty of room */
+	    minsize = ht->ht_used * 4;  // make plenty of room
     }
     else
     {
@@ -375,20 +375,20 @@ hash_may_resize(
     newsize = HT_INIT_SIZE;
     while (newsize < minsize)
     {
-	newsize <<= 1;		/* make sure it's always a power of 2 */
+	newsize <<= 1;		// make sure it's always a power of 2
 	if (newsize == 0)
-	    return FAIL;	/* overflow */
+	    return FAIL;	// overflow
     }
 
     if (newsize == HT_INIT_SIZE)
     {
-	/* Use the small array inside the hashdict structure. */
+	// Use the small array inside the hashdict structure.
 	newarray = ht->ht_smallarray;
 	if (ht->ht_array == newarray)
 	{
-	    /* Moving from ht_smallarray to ht_smallarray!  Happens when there
-	     * are many removed items.  Copy the items to be able to clean up
-	     * removed items. */
+	    // Moving from ht_smallarray to ht_smallarray!  Happens when there
+	    // are many removed items.  Copy the items to be able to clean up
+	    // removed items.
 	    mch_memmove(temparray, newarray, sizeof(temparray));
 	    oldarray = temparray;
 	}
@@ -397,13 +397,13 @@ hash_may_resize(
     }
     else
     {
-	/* Allocate an array. */
+	// Allocate an array.
 	newarray = ALLOC_MULT(hashitem_T, newsize);
 	if (newarray == NULL)
 	{
-	    /* Out of memory.  When there are NULL items still return OK.
-	     * Otherwise set ht_error, because lookup may result in a hang if
-	     * we add another item. */
+	    // Out of memory.  When there are NULL items still return OK.
+	    // Otherwise set ht_error, because lookup may result in a hang if
+	    // we add another item.
 	    if (ht->ht_filled < ht->ht_mask)
 		return OK;
 	    ht->ht_error = TRUE;
@@ -470,8 +470,8 @@ hash_hash(char_u *key)
 	return (hash_T)0;
     p = key + 1;
 
-    /* A simplistic algorithm that appears to do very well.
-     * Suggested by George Reilly. */
+    // A simplistic algorithm that appears to do very well.
+    // Suggested by George Reilly.
     while (*p != NUL)
 	hash = hash * 101 + *p++;