ripgrep: migrate to libripgrep

This commit does the work to delete the old `grep` crate and effectively
rewrite most of ripgrep core to use the new libripgrep crates. The new
`grep` crate is now a facade that collects the various crates that make
up libripgrep.

The most complex part of ripgrep core is now arguably the translation
between command line parameters and the library options, which is
ultimately where we want to be.

appveyor.yml

@@ -1,8 +1,6 @@
-# Inspired from https://github.com/habitat-sh/habitat/blob/master/appveyor.yml
 cache:
   - c:\cargo\registry
   - c:\cargo\git
-  - c:\projects\ripgrep\target
 
 init:
   - mkdir c:\cargo
@@ -19,14 +17,20 @@ environment:
     PROJECT_NAME: ripgrep
     RUST_BACKTRACE: full
   matrix:
-    - TARGET: i686-pc-windows-gnu
-      CHANNEL: stable
-    - TARGET: i686-pc-windows-msvc
-      CHANNEL: stable
     - TARGET: x86_64-pc-windows-gnu
       CHANNEL: stable
+      BITS: 64
+      MSYS2: 1
     - TARGET: x86_64-pc-windows-msvc
       CHANNEL: stable
+      BITS: 64
+    - TARGET: i686-pc-windows-gnu
+      CHANNEL: stable
+      BITS: 32
+      MSYS2: 1
+    - TARGET: i686-pc-windows-msvc
+      CHANNEL: stable
+      BITS: 32
 
 matrix:
   fast_finish: true
@@ -35,8 +39,9 @@ matrix:
 # (Based on from https://github.com/rust-lang/libc/blob/master/appveyor.yml)
 install:
   - curl -sSf -o rustup-init.exe https://win.rustup.rs/
-  - rustup-init.exe -y --default-host %TARGET% --no-modify-path
-  - if defined MSYS2_BITS set PATH=%PATH%;C:\msys64\mingw%MSYS2_BITS%\bin
+  - rustup-init.exe -y --default-host %TARGET%
+  - set PATH=%PATH%;C:\Users\appveyor\.cargo\bin
+  - if defined MSYS2 set PATH=C:\msys64\mingw%BITS%\bin;%PATH%
   - rustc -V
   - cargo -V
 
@@ -46,11 +51,11 @@ build: false
 # Equivalent to Travis' `script` phase
 # TODO modify this phase as you see fit
 test_script:
-  - cargo test --verbose --all
+  - cargo test --verbose --all --features pcre2
 
 before_deploy:
   # Generate artifacts for release
-  - cargo build --release
+  - cargo build --release --features pcre2
   - mkdir staging
   - copy target\release\rg.exe staging
   - ps: copy target\release\build\ripgrep-*\out\_rg.ps1 staging