Fix PCRE build under non-__GNUC__ compilers

PCRE's JIT has several paths that end in a #error under compilers that
don't #define __GNUC__.

This is because either
- those platforms were unavailable to PCRE devs so they were not tested;
- the #ifdef guards inline assembly fragments in GCC (AT&T) syntax;
- the #ifdef guards functions present f.i. in ARM's EABI and unavailable
  f.i. under WinCE.

This commit disables PCRE's JIT under ARM and MIPS unless __GCC__ is
defined. The MIPS #define from MSVC (_M_MRX000) is also dropped.

Change-Id: I59f959c321413845ffbdf1ac32740b400422e0ee
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Björn Breitmeyer <bjoern.breitmeyer@kdab.com>
Reviewed-by: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Reviewed-by: Andreas Holzammer <andreas.holzammer@kdab.com>

src/3rdparty/pcre/config.h

@@ -16,17 +16,19 @@
 /*
     man 3 pcrejit for a list of supported platforms;
     as PCRE 8.30, stable JIT support is available for:
-    - ARM v5, v7, and Thumb2
+    - ARM v5, v7, and Thumb2 (__GNUC__ compilers only)
     - x86/x86-64
-    - MIPS 32bit
+    - MIPS 32bit (__GNUC__ compilers only)
 */
 #if \
     /* ARM */ \
-    defined(__arm__) || defined(__TARGET_ARCH_ARM) \
+    (defined(__GNUC__) && (defined(__arm__) || defined(__TARGET_ARCH_ARM))) \
     /* x86 32/64 */ \
     || defined(__i386) || defined(__i386__) || defined(_M_IX86) \
     || defined(__x86_64) || defined(__x86_64__) || defined(__amd64) || defined(_M_X64) \
     /* MIPS32 */ \
-    || defined(__mips) || defined(__mips__) || defined(_M_MRX000) && !(defined(_MIPS_ARCH_MIPS64) || defined(__mips64))
+    || (defined(__GNUC__) \
+       && (defined(__mips) || defined(__mips__)) \
+       && !(defined(_MIPS_ARCH_MIPS64) || defined(__mips64)))
 #  define SUPPORT_JIT
 #endif