build: Move revision files into external_revisions

Moved glslang, spirv-tools and spirv-headers revision files into
the external_revisions subdirectory.  Modified the Win/Lin update
external sources files to use the new locations.

Change-Id: I56138d5ae21430bcc564e6a42723accae1bcb9de
diff --git a/glslang_revision b/external_revisions/glslang_revision
similarity index 100%
rename from glslang_revision
rename to external_revisions/glslang_revision
diff --git a/spirv-headers_revision b/external_revisions/spirv-headers_revision
similarity index 100%
rename from spirv-headers_revision
rename to external_revisions/spirv-headers_revision
diff --git a/spirv-tools_revision b/external_revisions/spirv-tools_revision
similarity index 100%
rename from spirv-tools_revision
rename to external_revisions/spirv-tools_revision
diff --git a/update_external_sources.bat b/update_external_sources.bat
index d5f2863..2d01a24 100644
--- a/update_external_sources.bat
+++ b/update_external_sources.bat
@@ -14,6 +14,7 @@
 set errorCode=0
 set BUILD_DIR=%~dp0
 set BASE_DIR="%BUILD_DIR%external"
+set REVISION_DIR="%BUILD_DIR%external_revisions"
 set GLSLANG_DIR=%BASE_DIR%\glslang
 set SPIRV_TOOLS_DIR=%BASE_DIR%\spirv-tools
 
@@ -121,23 +122,23 @@
 
 REM Read the target versions from external file, which is shared with Linux script
 
-if not exist glslang_revision (
+if not exist %REVISION_DIR%\glslang_revision (
    echo.
-   echo Missing glslang_revision file!  Place it next to this script with target version in it.
+   echo Missing glslang_revision file!  Place it in %REVSION_DIR% with target version in it.
    set errorCode=1
    goto:error
 )
 
-if not exist spirv-tools_revision (
+if not exist %REVISION_DIR%\spirv-tools_revision (
    echo.
-   echo Missing spirv-tools_revision file!  Place it next to this script with target version in it.
+   echo Missing spirv-tools_revision file!  Place it in %REVISION_DIR% with target version in it.
    set errorCode=1
    goto:error
 )
 
-set /p GLSLANG_REVISION= < glslang_revision
-set /p SPIRV_TOOLS_REVISION= < spirv-tools_revision
-set /p SPIRV_HEADERS_REVISION= < spirv-headers_revision
+set /p GLSLANG_REVISION= < %REVISION_DIR%\glslang_revision
+set /p SPIRV_TOOLS_REVISION= < %REVISION_DIR%\spirv-tools_revision
+set /p SPIRV_HEADERS_REVISION= < %REVISION_DIR%\spirv-headers_revision
 echo GLSLANG_REVISION=%GLSLANG_REVISION%
 echo SPIRV_TOOLS_REVISION=%SPIRV_TOOLS_REVISION%
 echo SPIRV_HEADERS_REVISION=%SPIRV_HEADERS_REVISION%
diff --git a/update_external_sources.sh b/update_external_sources.sh
index 6f87903..c20297a 100755
--- a/update_external_sources.sh
+++ b/update_external_sources.sh
@@ -3,9 +3,11 @@
 
 set -e
 
-GLSLANG_REVISION=$(cat "${PWD}"/glslang_revision)
-SPIRV_TOOLS_REVISION=$(cat "${PWD}"/spirv-tools_revision)
-SPIRV_HEADERS_REVISION=$(cat "${PWD}"/spirv-headers_revision)
+REVISION_DIR=$PWD/external_revisions
+
+GLSLANG_REVISION=$(cat ${REVISION_DIR}/glslang_revision)
+SPIRV_TOOLS_REVISION=$(cat "${REVISION_DIR}"/spirv-tools_revision)
+SPIRV_HEADERS_REVISION=$(cat "${REVISION_DIR}"/spirv-headers_revision)
 echo "GLSLANG_REVISION=${GLSLANG_REVISION}"
 echo "SPIRV_TOOLS_REVISION=${SPIRV_TOOLS_REVISION}"
 echo "SPIRV_HEADERS_REVISION=${SPIRV_HEADERS_REVISION}"