Change default build type to "minsize"

People (and distros) have been building ksh from this project using the
default "debug" build type since we switched from Nmake to Meson. That
results in a ksh program whose performance is far from optimal. So change
the default build type. If a debugging enabled binary is needed, such as
in a CI environment, it must be requested explicitly.

Related #1449

CHANGELOG.md

@@ -11,6 +11,9 @@
 
 ## Notable fixes and improvements
 
+- The default build type is now "minsize" since that dramatically improves the
+  performance of ksh. You can still request a debug build via `meson
+  --buildtype=debug` (issue #1449).
 - Fix `history` command behavior when the *~/.sh_history* file has
   specific content (issue #1432).
 - A ${.sh.install_prefix}/config.ksh file will be sourced if it exists. It is

meson.build

@@ -1,4 +1,9 @@
-project('ksh93', 'c', default_options: [
+project('ksh9', 'c', default_options: [
+    # This is the optimal production build type for this project. If you need
+    # a debug build you must explicitly run `meson --buildtype=debug`. This
+    # helps ensure that each distro (or user) gets a performance optimized build
+    # even if they don't know to add the `--buildtype=minsize` option.
+    'buildtype=minsize',
     'b_lundef=false',
     'default_library=static',
     'c_std=c99', # we require the C99 (aka ISO9899:1999) language standard

scripts/build-on-docker.sh

@@ -18,7 +18,8 @@ mkdir build
 cd build
 
 echo ==== Configuring the build
-if ! meson -Dwarnings-are-errors=true --prefix="$(mktemp -dt ksh.XXXXXX)"
+if ! meson -Dwarnings-are-errors=true --prefix="$(mktemp -dt ksh.XXXXXX)" \
+    --buildtype=debug
 then
     cat meson-logs/meson-log.txt
     exit 1

scripts/build-on-macos.sh

@@ -15,7 +15,8 @@ mkdir build
 cd build
 
 echo ==== Configuring the build
-if ! meson -Dwarnings-are-errors=true --prefix="$(mktemp -dt ksh.XXXXXX)"
+if ! meson -Dwarnings-are-errors=true --prefix="$(mktemp -dt ksh.XXXXXX)" \
+    --buildtype=debug
 then
     cat meson-logs/meson-log.txt
     exit 1