libtiff: Remove support for _MSC_VER < 1500

From 97e9225fa51a761e94a7493618a471647741a403 Mon Sep 17 00:00:00 2001
From: Even Rouault <[EMAIL REDACTED]>
Date: Sun, 7 Jan 2024 23:42:49 +0100
Subject: [PATCH] Remove support for _MSC_VER < 1500

---
 libtiff/tif_dirread.c | 36 ------------------------------------
 libtiff/tiffiop.h     |  2 +-
 2 files changed, 1 insertion(+), 37 deletions(-)

diff --git a/libtiff/tif_dirread.c b/libtiff/tif_dirread.c
index cea569d5..a6e65998 100644
--- a/libtiff/tif_dirread.c
+++ b/libtiff/tif_dirread.c
@@ -1016,16 +1016,7 @@ TIFFReadDirEntryFloat(TIFF *tif, TIFFDirEntry *direntry, float *value)
             err = TIFFReadDirEntryCheckedLong8(tif, direntry, &m);
             if (err != TIFFReadDirEntryErrOk)
                 return (err);
-#if defined(_WIN32) && (_MSC_VER < 1500)
-            /*
-             * XXX: MSVC 6.0 does not support conversion
-             * of 64-bit integers into floating point
-             * values.
-             */
-            *value = _TIFFUInt64ToFloat(m);
-#else
             *value = (float)m;
-#endif
             return (TIFFReadDirEntryErrOk);
         }
         case TIFF_SLONG8:
@@ -1130,16 +1121,7 @@ TIFFReadDirEntryDouble(TIFF *tif, TIFFDirEntry *direntry, double *value)
             err = TIFFReadDirEntryCheckedLong8(tif, direntry, &m);
             if (err != TIFFReadDirEntryErrOk)
                 return (err);
-#if defined(_WIN32) && (_MSC_VER < 1500)
-            /*
-             * XXX: MSVC 6.0 does not support conversion
-             * of 64-bit integers into floating point
-             * values.
-             */
-            *value = _TIFFUInt64ToDouble(m);
-#else
             *value = (double)m;
-#endif
             return (TIFFReadDirEntryErrOk);
         }
         case TIFF_SLONG8:
@@ -2904,16 +2886,7 @@ TIFFReadDirEntryFloatArray(TIFF *tif, TIFFDirEntry *direntry, float **value)
             {
                 if (tif->tif_flags & TIFF_SWAB)
                     TIFFSwabLong8(ma);
-#if defined(_WIN32) && (_MSC_VER < 1500)
-                /*
-                 * XXX: MSVC 6.0 does not support
-                 * conversion of 64-bit integers into
-                 * floating point values.
-                 */
-                *mb++ = _TIFFUInt64ToFloat(*ma++);
-#else
                 *mb++ = (float)(*ma++);
-#endif
             }
         }
         break;
@@ -3149,16 +3122,7 @@ TIFFReadDirEntryDoubleArray(TIFF *tif, TIFFDirEntry *direntry, double **value)
             {
                 if (tif->tif_flags & TIFF_SWAB)
                     TIFFSwabLong8(ma);
-#if defined(_WIN32) && (_MSC_VER < 1500)
-                /*
-                 * XXX: MSVC 6.0 does not support
-                 * conversion of 64-bit integers into
-                 * floating point values.
-                 */
-                *mb++ = _TIFFUInt64ToDouble(*ma++);
-#else
                 *mb++ = (double)(*ma++);
-#endif
             }
         }
         break;
diff --git a/libtiff/tiffiop.h b/libtiff/tiffiop.h
index 96e67435..7f25ae14 100644
--- a/libtiff/tiffiop.h
+++ b/libtiff/tiffiop.h
@@ -334,7 +334,7 @@ struct TIFFOpenOptions
 #define ftell(stream, offset, whence) ftello(stream, offset, whence)
 #endif
 #endif
-#if defined(_WIN32) && !(defined(_MSC_VER) && _MSC_VER < 1400) &&              \
+#if defined(_WIN32) &&                                                         \
     !(defined(__MSVCRT_VERSION__) && __MSVCRT_VERSION__ < 0x800)
 typedef unsigned int TIFFIOSize_t;
 #define _TIFF_lseek_f(fildes, offset, whence)                                  \