regex: update pcre to 8.44 (bug 6650, r=KyleS) (#1309)

* Update OSX PCRE dependency to 8.44

* Add OSX build instructions

* Update Windows PCRE dependency to 8.44

* Update Linux PCRE dependency to 8.44

extensions/regex/README.md

@@ -1,8 +1,24 @@
 # PCRE Build Instructions
-As of writing, we're using pcre v8.32
+As of writing, we're using pcre v8.44
+
+https://ftp.pcre.org/pub/pcre/
 
 ## Windows
 We build with the MinSizeForRelease VS configuration using the target architecture you want. This is how both win libs are built. The following settings were selected in the CMAKE configuration
 ![AenKaUByp0](https://user-images.githubusercontent.com/11095737/87211804-10db1200-c2d0-11ea-85d9-ede4ba177de1.png)
 
 In the PCRE project, go to C/C++ configuration properties and select the Runtime Library to be Multi-threaded (`/MT`) instead of Multi-threaded DLL (`/MD`)
+
+## Mac
+For x86 or x86_64 add -m32 or -m64 to `CFLAGS`
+
+`export CFLAGS='-mmacosx-version-min=10.7'`
+
+`./configure --enable-unicode-properties --enable-jit --disable-shared --enable-utf && make`
+
+## Linux
+For x86 or x86_64 add -m32 or -m64 to `CFLAGS`
+
+`export CFLAGS='-Wa,-mrelax-reloactions=no'`
+
+`./configure --enable-unicode-properties --enable-jit --disable-shared --enable-utf && make`