KOBAYASHI Shuji 0c55b85fb0 Simplify MRuby::Command#_run to avoid duplicated compilation ...

ref: https://github.com/mruby/mruby/pull/4959#discussion_r402086196

Compiles twice because it falls back to `build.filename(command)` when
`command` fails. This process was added at 9968af4 to support `ccache gcc`
etc. At that time, it seems that it was necessary because
`build.filename(command)` quoted the whole `command`, but now it does not
quote, so we can just run `build.filename(command)`.

### Example

  ```console
  $ echo 1 > src/a.c
  $ rake -v
  ```

#### Before this patch:

  ```console
  (snip)
  gcc -std=gnu99 -g -O3 -Wall -Wundef -Wdeclaration-after-statement -Werror-implicit-function-declaration -Wwrite-strings -I"/mruby/mruby/include" -MMD -o "/mruby/mruby/build/host/src/a.o" -c "/mruby/mruby/src/a.c"
  /mruby/mruby/src/a.c:1:1: error: expected identifier or '('
  1
  ^
  1 error generated.
  gcc -std=gnu99 -g -O3 -Wall -Wundef -Wdeclaration-after-statement -Werror-implicit-function-declaration -Wwrite-strings -I"/mruby/mruby/include" -MMD -o "/mruby/mruby/build/host/src/a.o" -c "/mruby/mruby/src/a.c"
  /mruby/mruby/src/a.c:1:1: error: expected identifier or '('
  1
  ^
  1 error generated.
  rake aborted!
  (snip)
  ```

#### After this patch:

  ```console
  (snip)
  gcc -std=gnu99 -g -O3 -Wall -Wundef -Wdeclaration-after-statement -Werror-implicit-function-declaration -Wwrite-strings -I"/mruby/mruby/include" -MMD -o "/mruby/mruby/build/host/src/a.o" -c "/mruby/mruby/src/a.c"
  /mruby/mruby/src/a.c:1:1: error: expected identifier or '('
  1
  ^
  1 error generated.
  rake aborted!
  (snip)
  ```

2020-11-13 21:49:12 +09:00

..

mruby

Simplify MRuby::Command#_run to avoid duplicated compilation

2020-11-13 21:49:12 +09:00

mruby-core-ext.rb

Use Rake.verbose instead of $verbose and $pp_show in build scripts

2019-12-28 17:03:37 +09:00