Tidy unnecessarily complicated macros in escapes table.

ChangeLog

@@ -168,6 +168,8 @@ auto-possessified, causing incorrect match failures.
 36. Removed the character type bit ctype_meta, which dates from PCRE1 and is 
 not used in PCRE2.
 
+37. Tidied up unnecessarily complicated macros used in the escapes table.
+
 
 Version 10.31 12-February-2018
 ------------------------------

src/pcre2_compile.c

@@ -512,17 +512,17 @@ static const short int escapes[] = {
      -ESC_Z,                  CHAR_LEFT_SQUARE_BRACKET,
      CHAR_BACKSLASH,          CHAR_RIGHT_SQUARE_BRACKET,
      CHAR_CIRCUMFLEX_ACCENT,  CHAR_UNDERSCORE,
-     CHAR_GRAVE_ACCENT,       ESC_a,
+     CHAR_GRAVE_ACCENT,       CHAR_BEL,
      -ESC_b,                  0,
-     -ESC_d,                  ESC_e,
-     ESC_f,                   0,
+     -ESC_d,                  CHAR_ESC,
+     CHAR_FF,                 0,
      -ESC_h,                  0,
      0,                       -ESC_k,
      0,                       0,
-     ESC_n,                   0,
+     CHAR_LF,                 0,
      -ESC_p,                  0,
-     ESC_r,                   -ESC_s,
-     ESC_tee,                 0,
+     CHAR_CR,                 -ESC_s,
+     CHAR_HT,                 0,
      -ESC_v,                  -ESC_w,
      0,                       0,
      -ESC_z
@@ -546,11 +546,11 @@ because it is defined as 'a', which of course picks up the ASCII value. */
 #endif
 
 static const short int escapes[] = {
-/*  80 */        ESC_a, -ESC_b,       0, -ESC_d, ESC_e,  ESC_f,      0,
+/*  80 */         CHAR_BEL, -ESC_b,       0, -ESC_d, CHAR_ESC, CHAR_FF,      0,
 /*  88 */ -ESC_h,        0,      0,     '{',      0,        0,       0,      0,
-/*  90 */     0,     0, -ESC_k,       0,      0, ESC_n,      0, -ESC_p,
-/*  98 */     0, ESC_r,      0,     '}',      0,     0,      0,      0,
-/*  A0 */     0,   '~', -ESC_s, ESC_tee,      0,-ESC_v, -ESC_w,      0,
+/*  90 */      0,        0, -ESC_k,       0,      0,  CHAR_LF,       0, -ESC_p,
+/*  98 */      0,  CHAR_CR,      0,     '}',      0,        0,       0,      0,
+/*  A0 */      0,      '~', -ESC_s, CHAR_HT,      0,   -ESC_v,  -ESC_w,      0,
 /*  A8 */      0,   -ESC_z,      0,       0,      0,      '[',       0,      0,
 /*  B0 */      0,        0,      0,       0,      0,        0,       0,      0,
 /*  B8 */      0,        0,      0,       0,      0,      ']',     '=',    '-',

src/pcre2_internal.h

@@ -1248,36 +1248,6 @@ contain characters with values greater than 255. */
 #define XCL_PROP      3    /* Unicode property (2-byte property code follows) */
 #define XCL_NOTPROP   4    /* Unicode inverted property (ditto) */
 
-/* Escape items that are just an encoding of a particular data value. These
-appear in the escapes[] table in pcre2_compile.c as positive numbers. */
-
-#ifndef ESC_a
-#define ESC_a CHAR_BEL
-#endif
-
-#ifndef ESC_e
-#define ESC_e CHAR_ESC
-#endif
-
-#ifndef ESC_f
-#define ESC_f CHAR_FF
-#endif
-
-#ifndef ESC_n
-#define ESC_n CHAR_LF
-#endif
-
-#ifndef ESC_r
-#define ESC_r CHAR_CR
-#endif
-
-/* We can't officially use ESC_t because it is a POSIX reserved identifier
-(presumably because of all the others like size_t). */
-
-#ifndef ESC_tee
-#define ESC_tee CHAR_HT
-#endif
-
 /* These are escaped items that aren't just an encoding of a particular data
 value such as \n. They must have non-zero values, as check_escape() returns 0
 for a data character. In the escapes[] table in pcre2_compile.c their values