[build] Move configs/ to assets/build/

I was sick of `configs` colliding with `configure`, and these are
(mostly) static asset files anyway, they should live under assets/.

assets/build/base.yaml

@@ -0,0 +1,39 @@
+---
+variables:
+  cc: "${source_root}/sysroot/bin/clang"
+  cxx: "${source_root}/sysroot/bin/clang++"
+  ld: "${source_root}/sysroot/bin/ld.lld"
+  ar: ar
+  nasm: nasm
+  objcopy: objcopy
+
+  ccflags: [
+    "-I${source_root}/src/include",
+    "-I${source_root}/src/include/x86_64",
+    "-fcolor-diagnostics",
+    "-U__STDCPP_THREADS__",
+    "-D_LIBCPP_HAS_NO_THREADS",
+    "-DVERSION_MAJOR=${version_major}",
+    "-DVERSION_MINOR=${version_minor}",
+    "-DVERSION_PATCH=${version_patch}",
+    "-DVERSION_GITSHA=0x${version_sha}",
+    '-DGIT_VERSION=\"${version_major}.${version_minor}.${version_patch}+${version_sha}\"',
+    '-DGIT_VERSION_WIDE=L\"${version_major}.${version_minor}.${version_patch}+${version_sha}\"',
+
+    "-Wformat=2", "-Winit-self", "-Wfloat-equal", "-Winline", "-Wmissing-format-attribute",
+    "-Wmissing-include-dirs", "-Wswitch", "-Wundef", "-Wdisabled-optimization",
+    "-Wpointer-arith", "-Wno-attributes", "-Wno-sign-compare", "-Wno-multichar",
+    "-Wno-div-by-zero", "-Wno-endif-labels", "-Wno-pragmas", "-Wno-format-extra-args",
+    "-Wno-unused-result", "-Wno-deprecated-declarations", "-Wno-unused-function",
+    "-Wno-address-of-packed-member", "-Wno-invalid-offsetof", "-Wno-format-nonliteral",
+    "-Werror" ]
+
+  asflags: [
+    "-DVERSION_MAJOR=${version_major}",
+    "-DVERSION_MINOR=${version_minor}",
+    "-DVERSION_PATCH=${version_patch}",
+    "-DVERSION_GITSHA=0x${version_sha}",
+    "-I${source_root}/src/include" ]
+
+  cflags: [ "-std=c11" ]
+  cxxflags: [ "-std=c++17" ]